Robert Day, the heir to an oil fortune who founded what is now known as the TCW Group, a giant asset-management firm, and later became an influential philanthropist, donating large sums to California medical, arts and scholarly institutions, died on Sept. 14 in Los Angeles. He was 79.
His death was announced by the W.M. Keck Foundation, the philanthropic organization of which he had been chairman since 1995. The announcement did not specify a cause.
Born into wealth — his grandfather, William Myron Keck, amassed a fortune through his independent oil company, Superior Oil — Mr. Day built his own empire in the Trust Company of the West. That firm, which was eventually renamed the TCW Group, became a major financial steward for corporate pension funds, endowments and wealthy individuals.
By the time TCW agreed to sell itself to Société Générale, a large French bank, for more than $1.3 billion in 2001, it oversaw some $80 billion in assets. The deal compounded Mr. Day’s personal wealth: Los Angeles Business Journal last year estimated his net worth at $2.9 billion.
“He had an oversized competitive drive that would have been the envy of the great Green Bay Packers’ football coach Vince Lombardi,” the former secretary of state James A. Baker III, a friend, wrote after Mr. Day’s death in a tribute on the website of Claremont McKenna College, Mr. Day’s alma mater. “His mantra was simple: Winning is the only thing. But at the same time, he always led with an esprit de corps that made experiences with him as enjoyable as they were hard-working.”
After selling his company, Mr. Day focused primarily on philanthropy, largely through the Keck Foundation, which his grandfather founded and which now oversees some $1.5 billion.
Robert Addison Day was born in Los Angeles on Dec. 11, 1943, to Robert Addison Day and Willametta Keck Day. His father was a director of Superior Oil who would later become president of the Los Angeles fire and harbor commissions; his mother was also a philanthropist. Disagreements with her brother, Howard B. Keck, over the future of Superior Oil led to the company’s sale to Mobil for $5.7 billion in 1984.
Mr. Day graduated from the Stevenson School in 1961 and from Claremont McKenna, where he wrote his senior thesis about how to found an asset management firm, in 1965. (His proposal earned a B-minus “for bravery.”)
After college, he moved to New York to work at the white-shoe investment bank White, Weld & Company. But he quickly moved on: In 1969, he started Cypress Partners, an early example of a hedge fund. Two years later he founded Trust Company of the West with $2 million in assets under management.
TCW became a significant investor in stocks, bonds, real estate and other assets, managing money on behalf of clients like Boeing, Xerox and the California State Teachers’ Retirement System. It also produced superstar financiers, including the Oaktree Capital founders Howard Marks and Bruce Karsh and the DoubleLine Capital founder Jeffrey Gundlach.
Mr. Day was later drawn into a dispute between TCW and Mr. Gundlach, who was fired from the firm in 2010: An ally of Mr. Gundlach’s claimed that Mr. Day had told Mr. Gundlach that he was fired in part for missing staff parties held by Mr. Day and for making “too much money.”
Even after selling TCW to Société Générale, which was said to have earned him hundreds of millions of dollars, Mr. Day retained ties to the business world. He served on the French bank’s board as its first American director, as well as on the boards of Freeport-McMoRan and Fisher Scientific.
And he was the chairman and major shareholder of Foley Timber and Land Company, which controlled a 560,000-acre plot of land — about the size of Rhode Island — in Florida, making it one of the state’s biggest landowners. Foley Timber later sold a majority of its holdings to another financial mogul, Thomas Peterffy.
Much of Mr. Day’s philanthropy centered on Claremont McKenna, where he joined the board of trustees in 1970 and stayed on for five decades. In 2007, he donated $200 million to the school to create the Robert Day Scholars Program; it was one of the biggest gifts ever given to an American college or university. The donation led the school to rename its economics department after him.
In 2021, a $40 million donation from the Keck Foundation led to the creation of the school’s Robert Day Sciences Center.
“Robert’s personal, professional and philanthropic commitment to Claremont McKenna is extraordinary,” Hiram Chodosh, the school’s president, said in a statement. “The legacy of his impact is incalculable.”
In 2008, Mr. Day said of his gifts to the school, “I believe that I should put something back into the system, because if I don’t put something back, the next generation will not have the same benefits I enjoyed.”
Through the Keck Foundation — which says it has given more than 6,500 awards, worth $2.2 billion, since 1954 — Mr. Day gave to an array of other institutions. Many were in his native Southern California, including medical initiatives and institutions at the University of Southern California and the University of California, Los Angeles, as well as the Los Angeles County Museum of Art.
He is survived by his wife, Marlyn; two sons, Joe and Jon; a daughter, DiDi Day; a brother, Matt; and several grandchildren. (He was previously married to Marina Forstmann and to Kelly Gilmore.) His brothers Lawrence and T.J. and his sister, Tammis, died before him.