General Motors Co. is suing a former board member, claiming he leaked confidential information to a rival company and to the United Auto Workers, a move the auto maker says added billions to its labor costs.
In a federal lawsuit filed in New Jersey this week, the company accused Joseph Ashton, a former vice president at the UAW, of accepting bribes from crosstown competitor Fiat Chrysler Automobiles NV, which was at the time trying to pressure GM into a merger. Mr. Ashton served as a director at GM at the time of the merger…