Contract Talks at McDonnell: Bargaining officials of the aerospace giant and United Aerospace Workers Local 148, which represents about 9,000 of McDonnell's Douglas Aircraft Co. workers in Long Beach, are set to begin new contract negotiations today. The workers build the company's commercial jetliners and its C-17 military transport. The union's existing four-year contract expires April 16. The union is expected to press for more job security and salary gains, especially in light of McDonnell Douglas' record profit last year. The St. Louis-based concern earned $598 million in 1994 on revenue of $13.2 billion.