Hammer was the owner and chief executive of the Knoedler, an art dealership in New York City, which closed in 2011 after purchasing and reselling $80 million in forged paintings bearing the signature of abstract expressionists such as Mark Rothko and Jackson Pollock.
His paternal grandmother, Russian-born actress Baroness Olga von Root, was the daughter of a czarist general.
[7] Before becoming involved with his grandfather's company, Occidental Petroleum, Hammer worked in different roles at the New York City securities and investment banking firm Kidder, Peabody & Co.,[8] which later was sold to PaineWebber, which ultimately merged with UBS AG in November 2000.
In 1985, he moved to the corporation's headquarters in Los Angeles where he became a vice president, He shortly thereafter became a member of the board of directors and the executive committee, and worked in those capacities until his departure from the company in 1991, not long after the death of Armand Hammer.
[citation needed] Hammer formerly resided in a Paul Williams-designed, 1920s Tudor-style mansion, that was featured in films and television shows, including the Bells of St. Mary's, Rocky V, and others.