Continental Airlines Inc.'s pilots union said it plans to hire its own financial advisors to evaluate a possible merger with Delta Air Lines Inc. The union did not say whether it supported such a combination. . . . Alamo Rent A Car said Keith Cobb will resign as chief executive and vice chairman, but will remain through the transition period of its acquisition by Republic Industries Inc. . . . General Motors Corp. said it reached a three-year labor agreement with the International Union of Electronic Workers that represents 20,000 hourly workers. . . . Presstek Inc. said the Securities and Exchange Commission began a formal investigation of trading in the company's shares and subpoenaed documents and testimony by its executives.