New Regency Prods. has promoted Adam R. Platnick to executive vice president.Platnick, who has been a senior VP of Arnon Milchan’s indie since September 1990, will oversee corporate development, investor relations, foreign distribution and business and legal affairs. Before joining New Regency, Platnick was a senior VP of worldwide business affairs for Vestron Inc., the Stamford, Conn.-based video company. Before Vestron, Platnick was responsbile for motion pictures and TV accounts for the New York law firm Grubman, Indursky and Schindler. Among his clients there were Robert De Niro and his Tribeca Film Center.