DEL MAR, Calif. - Tom Mankiewicz, a Hollywood writer and director who owned the Grade 1 winners Dearest Trickski and Victory Encounter, died of cancer on Saturday, the Del Mar publicity department announced on Sunday. A native of Los Angeles, Mankiewicz was 68. In Hollywood, Mankiewicz was well known for sharing screenwriting credits on the James Bond films “Diamonds Are Forever,” “Live And Let Live,” and “The Man With The Golden Gun,” for directing the 1987 comedy “Dragnet,” and for helping to create the television series “Hart to Hart.” In Thoroughbred racing, Mankiewicz owned Victory Encounter, the winner of the Grade 1 Vanity Handicap at Hollywood Park in 2004, and Dearest Trickski, the winner of the Grade 1 La Brea Stakes at Santa Anita in 2007. He claimed Dearest Trickski for $32,000 and watched her win four stakes. Mankiewicz also served briefly on the board of directors of the Thoroughbred Owners of California.