Vera Kostoff, former stage actress and L.A. Times syndicate staffer, died of natural causes July 23 in Palm Springs. She was 90.A native of Sofia, Bulgaria, and a Miss Bulgaria winner, Kostoff appeared in productions of “Ivanhoe,” “Medea” and “Pygmalion.” She worked 27 years, most recently as a supervisor for its syndicate service. She is survived by her three daughters and their husbands, including author Sidney Sheldon. Her husband Atanas and a granddaughter preceded her in death. Services and burial were private. Memorial contributions in her name can be made to Bighorn Institute, P.O. Box 262, Palm Desert, CA 92261-0262.