Tesoro Petroleum Corporation History

Company Perspectives:

Tesoro is a growing marketing company, committed to using customer-driven strategies that create opportunities from the numerous changes occurring in our industry. We use a team approach to market our products and cultivate business relationships with the objective of increasing value for our customers and shareholders.

Key Dates:

1964:

Robert V. West, Jr., founds Tesoro Petroleum Corporation as a spinoff of Texstar Corporation.

1968:

Tesoro merges with Intex Oil Company and Sioux Oil Company.

1969:

The company acquires half-interest in British Petroleum's oil-producing operations in Trinidad and Tobago, with the island nation's government holding the other half; Tesoro begins construction of an oil refinery on the west coast of Alaska.

1971:

The company enters the marketing sector through the purchase of the S&N Investment Company and the Digas Company, operator of gasoline service stations.

1974:

Following the purchase of two sizable exploratory tracts in Bolivia, Tesoro Inter-American Production Company is formed and takes responsibility for Caribbean and Latin American operations.

1975:

The company spends $83 million for a 36.7 percent interest in the Puerto Rican firm Commonwealth Oil Refining Company (Corco).

1977:

Tesoro writes off $59 million of its investment in Corco, which soon files for bankruptcy.

1980:

The company fends off the first of several takeover attempts, this one by Diamond Shamrock Corporation.

1985:

The company sells its share of Trinidad-Tesoro to the island nation's government.

1988:

Tesoro sells its domestic oil and gas producing properties to American Exploration.

1995:

The company sells some of its oil and gas production properties in Texas to Coastal Corporation for $74 million.

1998:

The company acquires two refineries in Hawaii and Washington state, as well as 32 retail gas stations in Hawaii.

1999:

The company's exit from exploration and production is completed by selling domestic operations to EEX Corporation and the Bolivian-based activities to BG PLC.

2000:

An agreement is reached with Wal-Mart Stores, Inc. to open and operate filling stations at Wal-Mart outlets under the name Mirastar.

2001:

Tesoro acquires refineries in Utah and North Dakota and 45 gas stations in a $677 million deal with BP p.l.c.

Company History:

Tesoro Petroleum Corporation is an independent energy company principally involved in refining, distributing, and marketing petroleum products. With five refineries in Alaska, Hawaii, North Dakota, Utah, and Washington state having a combined capacity of 390,000 barrels per day, Tesoro is one of the largest independent refining and marketing firms in the western United States. On the marketing side, the company distributes its products in Alaska, Hawaii, and other western states through about 640 branded outlets, 160 of which are owned by the company. Through an agreement with Wal-Mart Stores, Inc., Tesoro sells its gasoline at selected Wal-Mart locations in the western United States, with these stations operating under the Mirastar brand, which was developed by the company exclusively for the retailing giant. Outside of its core refining and marketing activities, Tesoro also distributes petroleum products and provides logistical support services to the marine and offshore exploration and production sectors.

In its early years Tesoro grew rapidly through the acquisition of a wide spectrum of energy businesses. This growth weakened the company's financial status, however, and it was later forced to shed many of its subsidiaries and devote a large amount of its attention to avoiding takeover, both internal and external, and battling with dissident shareholders. Later, by the late 1990s, the company appeared to have found a formula for success by abandoning its upstream operations and beefing up its core downstream activities.

Spate of Acquisitions in Early Years

Tesoro was founded by Robert V. West, Jr., in 1964. West had earned a doctorate in chemical engineering and then spent his entire career in the petroleum industry, rising to become president of Texstar Petroleum Company, a subsidiary of a larger company, Texstar Corporation, that was controlled by Texas wildcatter Tom Slick. After Slick's death in a plane crash, West convinced the executors of Slick's estate to sell the company West ran, with its oil-producing properties, to him. West borrowed $6.5 million to purchase the stock of Texstar Petroleum from its parent company and merged Texstar into the new company he had set up, Tesoro, which means "treasure" in Spanish.

In its previous incarnation, Tesoro had been a small but profitable oil and gas company. In its new form, however, the company carried such a high debt burden that it was difficult for Tesoro to save the money necessary to expand. West embarked on an effort to financially stabilize his company by joining it with another, stronger entity. After three years of searching, West found two publicly owned companies that suited his needs, and in a complicated series of transactions, the three merged. With funding from Chicago's Continental Illinois bank, the Intex Oil Company--which had been founded in California in 1939 as the Exploration and Development Company--was joined with the Sioux Oil Company and with Tesoro. The new entity took the name of Tesoro in December 1968.

With this transformation, Tesoro became a company possessing a pool of stockholders, solid financial standing, a listing on the American Stock Exchange, and workable arrangements with investment banking houses, allowing it to raise capital for further expansion. West embarked on a ten-year spree of acquisitions in the energy business, picking up a mixed bag of companies at bargain-basement prices. The first step in this direction was taken when Tesoro sold $25 million worth of stock in late 1968. With this money, the company paid off its bank debt entirely, leaving $18 million in cash for investment.

Among Tesoro's first acquisitions were the Clymore Petroleum Corporation and the Trident Offshore Company, Ltd., in which Tesoro purchased a 55 percent interest. Tesoro's most important new venture involved the island government of Trinidad and Tobago. The company discovered that the British Petroleum Company (BP) planned to divest itself of its oil-producing operations in Trinidad and that the country's government intended to buy them. Since the Trinidadian government had no experience in the petroleum business, Tesoro was able to convince it to enter into joint ownership of the properties, forming Trinidad-Tesoro Petroleum Company Limited. Incorporated in Trinidad in 1969, the company was 50.1 percent owned by the island's government, with the remainder owned by Tesoro. Both partners contributed $50,000 to the venture, which subsequently purchased BP's holdings, including properties, equipment, and remaining oil products for $28 million. The rest of the money necessary for this purchase was raised through loans from banks and a deferred payment plan with BP. Once it had taken over BP's operations in Trinidad, Tesoro was able to restore them to profit-making status by renovating existing wells and making production less wasteful.

In addition to its operations in Trinidad, Tesoro also commenced construction of a refinery for crude oil on the west coast of Alaska at Kenai in early 1969. Building this facility took more than a year, and when it was completed, Tesoro experienced difficulty in operating it profitably. The problem of bringing crude oil to the refinery and transporting finished products to market had yet to be resolved in an economical fashion. In addition, the company faced stiff competition from the much larger Standard Oil Company (California), which owned the only other refinery in Alaska, producing a difficult competitive marketplace. "We held our noses and went underwater for a while," West told Forbes magazine in 1973, explaining the refinery's money-losing operations. Eventually, however, prices for refined petroleum products did rise, and the Alaskan refinery became profitable.

Tesoro also continued to purchase companies with a broad range of functions in the petroleum industry, including truck and pipeline transportation, petroleum equipment manufacturing and rental, and crude oil production. In looking for acquisitions, the company sought out properties that not only were profitable but also showed promise of continuing to return profits over the long term. Accordingly, Tesoro purchased Cardinal Transports, Inc., in early 1969. In March of the following year, the company added a Texas firm called Petroleum Distributing Company as well as the Land & Marine Rental Company and the Louisiana Barreling Company. Later that year, Tesoro invested in the Arnold Pipe Rental Company, Ltd., D&W Investments, Inc., and certain portions of Spira Chek, Inc. In early 1971 Tesoro continued its vertical integration when it took on the operation of gasoline service stations by buying the S&N Investment Company and the Digas Company, both located in southern California. These chains were subsequently expanded into many areas of the United States.

With its diverse operations, and activities in both Trinidad and Alaska running smoothly, Tesoro readied itself for further expansion with another sale of stock. In a symbolic move, the company switched its listing from the American Stock Exchange to the New York Stock Exchange, becoming the only San Antonio-based firm to be listed on the so-called Big Board. In August 1971 Tesoro raised $32.2 million in an equity offering. With these funds, the company increased its geographical reach once again, buying Redco, a subsidiary of Asamera Oil, which owned land on Boreno in Indonesia that could be explored for oil, as well as the rights to any oil found.

West also began negotiations with an Arab ruler to refine and market crude oil produced in his country. With the expectation that these talks would bear fruit, Tesoro established in September 1972 a wholly owned European subsidiary, Tesoro-Europe Petroleum B.V., to market petroleum products. In addition, the company bought the Dutch firm DeHumber Handelmaatschappij B.V. and four associated companies for $4 million. These companies handled wholesale and retail marketing operations. Tesoro's European interests were subsequently further expanded when the company acquired an interest in the rights to explore for petroleum in the Dutch sector of the North Sea oil field.

During this time, Tesoro continued to expand its American holdings, purchasing the Charles Wheatley Company in February 1972. This privately owned firm manufactured valves for use in the oil industry. In May 1973 Tesoro bought FWI, Inc. from Falcon Seaboard, Inc. in Houston. During the next year Eagle Transport Company and Turner Drill Pipe, two petroleum industry services located in Texas, also were brought on board. By the end of 1973 Tesoro was able to report that its steady pace of acquisitions in all sectors of the petroleum industry had allowed it to quintuple its earnings in just five years in business.

In 1973 the Organization of Petroleum Exporting Countries (OPEC) oil embargo caused an energy crisis in the United States, raising awareness of the importance of alternative energy sources to petroleum. Accordingly, Tesoro moved for the first time to incorporate other forms of fossil fuels in its operations. In September 1974 the company formed Tesoro Coal Company. Four months later it increased its coal holdings when it bought the Buckhorn Hazard Coal Company.

Geographically, Tesoro moved onto yet another continent when it bought into two sizable exploratory tracts in Bolivia. This led to the formation in 1974 of Tesoro Inter-American Production Company, which took over the company's holdings in Trinidad and also took responsibility for future operations in the Caribbean and Latin America. By the end of the 1974 fiscal year, Tesoro had gross revenues exceeding $500 million and earnings of about $60 million. The company had operations in 30 states and five foreign countries.

Souring of Corco Investment: Late 1970s

Operating from this position of strength, Tesoro made a serious error in June 1975, when it paid $83 million for 36.7 percent of the stock of the Commonwealth Oil Refining Company (Corco), a Puerto Rican oil refiner and petrochemical processor that was one and a half times as large as Tesoro. Corco had been caught short by the sharp rise in petroleum prices in 1974, and its profitability had fallen, bringing the cost of its stock down as well. Tesoro sent out a team of new managers to try to turn around the fortunes of its new subsidiary.

Despite the fact that Tesoro's debt had grown in size to 1.3 times its equity, the company continued its pace of acquisitions, purchasing the GO Drilling Company of Texas, which owned three oil drilling rigs. In the following year, the company expanded its Alaskan operations when it bought the Nikiski Alaska Pipeline Company. Tesoro diversified into a third area of the energy industry, forming Tesoro Natural Gas Company in April 1977 to purchase and transport natural gas.

By this time, however, Tesoro's financial position had become perilous, and the company's era of rapid expansion through haphazard acquisition came to a close. In 1977 Tesoro was forced to write off $59 million in Corco investments and lost $58 million overall. This bad news prompted a suit by shareholders against the company, alleging that Tesoro's Corco investment constituted mismanagement. It was clear that the company had bitten off more than it could chew.

Tesoro's lenders, concerned about the company's level of past borrowing, forced the company to liquidate many of its properties to earn cash to pay off some of its debt. Tesoro sold off its North Sea oil interests as well as an equipment manufacturer. The company also was forced to sell all but five of its American oil and gas properties, including refineries in Montana and Wyoming. This divestiture continued throughout 1978, which was capped by Corco's declaration of Chapter 11 bankruptcy. Tesoro subsequently reduced its interest in this subsidiary, surrendering its stock in 1981 and selling off its final ownership of Corco for $2.8 million in 1983. Overall, Tesoro had sacrificed a vast amount of capital in its bid to make Corco succeed.

Further difficulties arose in December 1978 when various investigations by the Internal Revenue Service (IRS), the Securities and Exchange Commission (SEC), and the U.S. Justice Department resulted in the company having to pay tax penalties. It also had to disclose that it had paid more than $1.3 million in bribes to officials in Bolivia and other foreign countries over a six-year period. This commenced a five-year federal investigation of Tesoro by a grand jury, which was not closed until February 1984.

In an effort to rebuild, Tesoro brought in management consultants in 1979 to help it create a plan for future growth. West told Business Week that Tesoro had undergone "a general change in philosophy" that would result in a more careful, integrated, and planned program of expansion and acquisition. As part of its new strategy, the company invested $45 million to upgrade its Alaskan refining facility, confident that the facility's remote location and ready source of raw materials in the Alaska oil fields would continue to make it a profitable enterprise.

Fending Off Takeover Bids in the 1980s

By 1980 Tesoro had reduced its debt load to 20 percent of equity from 80 percent and was once again in the black. Belying his vow to stick to sensible investment in the petroleum industry, West made an abortive attempt to purchase Gulfstream American, a manufacturer of corporate jets, early in the year. After this was abandoned, Tesoro itself became the object of a potential corporate takeover in August when the Diamond Shamrock Corporation, a chemicals and natural resources producer, purchased 4.5 percent of the company's stock and announced that it would buy the company in an effort to move into the petroleum industry. Tesoro quickly filed two lawsuits to block this attempt. When Trinidad's government announced that it would not work with Diamond Shamrock, the attempt was dropped.

Tesoro remained in danger of corporate takeover, however. Its debt-ridden coal operation as well as new tax laws in Trinidad that penalized Trinidad-Tesoro kept earnings and the company's stock value low. Amid the disorder, speculators on Wall Street began to buy up the company's stock, anticipating its takeover or its split into several parts.

In June 1982 this speculation bore fruit when Tesoro announced a plan to sell its domestic oil, gas, and coal properties, as well as its interest in the Trinidadian company, and split its remaining holdings into two companies. The proposal, however, was subject to approval by the company's board. Ultimately, only the company's money-losing coal operations were sold, for $4.35 million, to the Shamrock Coal Company.

Despite the sale, Tesoro's persistently poor performance and low stock price continued to anger some investors, causing dissent among the ranks of the company's stockholders. When some began to agitate for replacement of Tesoro's management team through a proxy fight, West sold a large chunk of stock in the company to a subsidiary of the Charter Company, an oil and insurance concern that was run by a friend. Subsequently, Tesoro tried to take over another small oil company, Enstar, and failed when it was sold to other suitors. The company instead purchased a 50 percent interest in offshore exploratory oil and gas properties owned by the Pel-Tex Oil Company.

In 1985 Tesoro further restructured its stock offerings to prevent any corporate takeover attempts. In addition, after years of proposals to do so, the company sold its nearly one-half share in Trinidad-Tesoro Petroleum to the island nation's government. The company announced plans to take over another oil producer but canceled them when, later in the year, its bond ratings were lowered, reflecting a loss of confidence in Tesoro's financial health. The company reported a loss of $87 million at the end of 1985.

Matters continued to worsen in 1986, as Tesoro wrote off $44.3 million on an attempt to find oil in Trinidad and also gave up the value of its Indonesian reserves. Exploration in other areas of the world fared no better; wells in Turkey also turned up dry. In Bolivia, the country's government proved unable to pay Tesoro for its services and then announced that it would reimburse the company not in cash but in goods. Tesoro's $30 million joint venture with Pel-Tex also yielded little.

The one bright spot in the company's portfolio was its Alaskan refinery. Tesoro announced that it would upgrade the facility, which turned a profit providing fuel for the Alaska market, including substantial military operations. Nevertheless, Tesoro's 1986 balance sheet showed losses of $124.8 million, and the company continued to fend off takeover attempts. In April 1986 Calvacade Oil made an offer to buy the company but was rejected.

In 1987 two more suitors had arrived--Oakville, a Hong Kong investment concern, and Pentane Partners, formed specifically to take over the company. Tesoro's problems had grown to include an $800 million shareholder suit, filed in July 1987 against the company's management for corruption and securities fraud, as well as other legal difficulties. Tesoro won its court case but not without suffering the embarrassing revelation that it had hired prostitutes for foreign officials. In addition, an FBI investigation into jury tampering was initiated, and the IRS demanded more than $50 million in back taxes.

By the end of 1987, Pentane Partners owned 9.74 percent of the company, and Oakville held 6.2 percent of Tesoro's stock. The company reported losses of $1.7 million and joined the list of Forbes's 500 poorest performing firms in sales growth. In May 1988 Tesoro's board rejected a bid by Pentane for the remainder of the company. In the next few months, the company reached an agreement with the IRS to pay only $20.6 million in back taxes and sold its domestic oil and gas producing properties to American Exploration for $21 million in an effort to shore up its financial standing. By August 1988 the company was also 5.3 percent owned by the chairman of another oil company, Stone Petroleum.

In 1988 Pentane made two additional attempts to acquire Tesoro, and the company also saw a $190 million offer by Harken Oil and Gas made and dropped. After a $56 million fine from the federal government for violating regulations on petroleum pricing and allocation, Tesoro reported a $30.5 million loss for the 1989 fiscal year.

Fights with Dissident Shareholders in the Early 1990s

By the following year, the company was back in the black with earnings of $22.7 million, but 1991 proved a disappointment, as the war in the Persian Gulf drove up prices for crude oil, while prices for refined products remained stable. This meant that profits on Tesoro's principal money-earning property, its Alaska refinery, were held down. The company earned only $3.9 million in 1991 and omitted its fourth quarterly dividend payment on stocks. Difficulties continued in 1992, as the company laid off 60 employees and closed offices in an effort to reduce costs. For 1992, Tesoro posted a net loss of $65.8 million on revenues of $946.4 million.

By the early 1990s, Metropolitan Life Insurance Company had gained a 28 percent stake in Tesoro after Charter Company went bankrupt and Metropolitan Life acquired the stake that Charter had held. With three members on the Tesoro board, Metropolitan was able to use its considerable leverage to force the ouster of West. In 1993 Metropolitan reached an agreement with Tesoro on a recapitalization plan in which Tesoro would buy back the stake over the course of several years. Tesoro began doing so in 1994, leading to the resignation of the Metropolitan representatives from the Tesoro board.

With Michael D. Burke leading the company as president and CEO, Tesoro faced additional disgruntled shareholders in the mid-1990s. At the annual meetings of both 1994 and 1995, a group of dissident shareholders led by Kevin Flannery, head of Whelan Management Group, attempted but failed to oust the firm's board of directors. The dissidents were unhappy with the way that the board was managing the company and specifically sought to sell Tesoro's refinery in Alaska to focus on exploration and production. The company actually moved in the opposite direction in September 1995 when it sold some of its oil and gas production properties in Texas to the Coastal Corporation for $74 million. That same month, Burke resigned from the company and was succeeded by Bruce A. Smith, who was promoted from his position as chief operating officer.

Smith was able to put an end to the shareholder revolt in early 1996. After Flannery and company launched a third bid to oust the company board, negotiations led to an agreement in April 1996. Tesoro agreed to increase the size of the board to nine members by naming three new directors, including a member of the dissident shareholders, Alan Kaufman. In addition, the shareholder group agreed to drop all pending legal action and to not seek to take control of the company or support any effort to do so for three years.

Focusing on Downstream Operations in the Late 1990s and Beyond

Freed from the distractions of takeover battles and disgruntled shareholders, Tesoro was able to focus on developing a longer range plan to secure the company's future. Eventually, near the end of the century, the company decided to focus on its downstream operations. To that end, Tesoro in May 1998 completed the acquisition of a refinery and retail outlets in Hawaii that had been owned by Broken Hill Proprietary Co. Ltd. The $252.2 million deal included a 95,000-barrel-per-day refinery, located about 22 miles west of Honolulu at Kapolei, and 32 retail gasoline service stations. Tesoro then gained its third refinery in August 1998 when it acquired a 108,000-barrel-per-day refinery in Anacortes, Washington, from Shell Oil Company for $280.1 million. The acquisitions increased the company's revenues to $1.49 billion for 1998, a significant increase over the $937.9 million figure of the preceding year.

This expansion also increased the company's debt load from $148 million to $520 million, which highlighted the need for a paring down of operations. In early 1999, then, the company announced that it would seek to sell or spin off its exploration and production operations. The divestment of the upstream side of the company was completed in December 1999 through two transactions. The domestic assets were sold to EEX Corporation for $215 million, while the Bolivian exploration and production operations were sold to U.K.-based BG PLC for $100 million. The divestments enabled Tesoro to reduce its debt to less than $400 million.

In addition to its newly bolstered refining operations, Tesoro in early 2000 also had a retail network consisting of about 245 stations, 64 of which were company owned and operated. In January 2000 the company moved to expand its retail side by entering into an agreement with Wal-Mart Stores, Inc. to build and operate filling stations at Wal-Mart stores in 11 western states--later expanded to 17 states. The companies later agreed to use a new brand, Mirastar, for the stations. By the end of 2000, there were 20 Mirastar outlets in operation, with plans for an additional 80-90 units to be opened each year from 2001 to 2003. Tesoro reported 2000 earnings of $73.3 million on revenues of $5.1 billion.

In September 2001 Tesoro further expanded both its refining and retailing operations through a $677 million deal with BP p.l.c. Acquired thereby were a refinery in Salt Lake City with a capacity of 55,000 barrels a day and a 60,000-barrel-per-day refinery in Mandan, North Dakota. This brought Tesoro's total refinery capacity to 390,000 barrels per day. Also included in the deal were 45 retail gasoline stations, contracts to supply 300 Amoco-branded stations, as well as associated pipelines, bulk storage facilities, and product distribution terminals. Around this same time, Tesoro announced that it would spend more than $85 million on a major upgrade of its refinery in Washington. The company also said that it was exploring its options regarding its marine services unit. A divestment of the unit would enable Tesoro to be fully focused on refining and retailing and perhaps to pay down some of its debt, which had increased to more than $1 billion following the BP deal. In November 2001 Tesoro acquired 37 retail gas stations with convenience stores from Gull Industries, Inc. The stations were located in Washington, Oregon, and Idaho.

Looking back, Tesoro had moved far beyond the scattershot ways of its not too distant past, when it consisted of a far-flung collection of mostly unrelated parts. With a sell-off of the marine services unit a distinct possibility, Tesoro seemed to be on the verge of completing its transformation into a leading independent refining and retailing company concentrating on the western United States. The company was very interested in bolstering its presence in the huge California market, and it seemed likely that the firm would pursue the acquisition of a refinery--as well as retail outlets--in that state. Opportunities stemming from the continued consolidation and reshuffling of the U.S. oil industry were bound to arise. Overall, Tesoro Petroleum seemed well on its way to putting its troubled past behind it.

Principal Subsidiaries: Tesoro Alaska Company; Tesoro Hawaii Corporation; Tesoro Marine Services Holding Company; Tesoro Marine Services, Inc.; Tesoro Petroleum Companies, Inc.; Tesoro Refining, Marketing & Supply Company; Tesoro West Coast Company.

Principal Competitors: Exxon Mobil Corporation; BP p.l.c.; ChevronTexaco Corporation; Phillips Petroleum Company; Valero Energy Corporation; Arctic Slope Regional Corporation.

Further Reading:

• Baltimore, Chris, "Texas Supreme Court Hands Tenneco Loss in Take-or-Pay Suit," Oil Daily, August 19, 1996, pp. 1+.
• Barrionuevo, Alexei, "Tesoro Petroleum Sells Its Operations in Bolivia to BG," Wall Street Journal, December 31, 1999, p. B5.
• Brammer, Rhonda, "Bargain Hunter," Barron's, March 14, 1994, pp. 20-21.
• Burrough, Bryan, "Collapse of an Old-Boy Oil Network Places Tesoro in Vulnerable Position for Takeover," Wall Street Journal, June 12, 1984.
• "EEX to Buy Tesoro's Upstream Holdings," Oil Daily, October 12, 1999.
• Fan, Aliza, "Spring Finally Breaks for Tesoro Petroleum As Chill of Shareholder Battle, Lawsuit Pass," Oil Daily, May 31, 1996, pp. 3+.
• ------, "Tesoro Fires Back at Dissidents, Wins Order Blocking Vote on Board, Bylaws," Oil Daily, January 11, 1996, p. 3.
• ------, "Unhappy Tesoro Shareholders Try Takeover of Board to Improve Company's Standing," Oil Daily, May 10, 1995, pp. 1+.
• Fletcher, Sam, and Peter Eisen, "Tesoro to Sell Bolivian Upstream to BG, Focus on Downstream," Oil Daily, November 23, 1999.
• Kovski, Alan, "Tesoro Agrees to Buy Hawaii Refinery from BHP for $275 Million," Oil Daily, March 20, 1998, p. 5.
• Lorek, Laura, "Tesoro Looking at Ways to Change Refinery Product Mix," Oil Daily, May 6, 1992, p. 4.
• "Opportunity Talks," Forbes, November 15, 1973.
• Phalon, Richard, "'Tis a Far, Far Better Thing," Forbes, March 1, 1982.
• "Tesoro Petroleum Corporation: An Address by Dr. Robert V. West, Jr., Chairman of the Board and Chief Executive Officer, at the Harvard Business School, February 19, 1975," San Antonio: Tesoro Petroleum Corporation, 1975.
• "Tesoro Petroleum: The Irony of Becoming a Takeover Target," Business Week, October 6, 1980.
• "Tesoro Petroleum Planning Major Upgrade for Refinery," San Antonio Business Journal, August 25, 2000, p. 6.
• Vogel, Todd, "Why Is Tesoro So Popular?," Business Week, December 21, 1987.

Source: International Directory of Company Histories, Vol. 45. St. James Press, 2002.