LaNeve, 50, is resigning effective Oct. 15 to accept a job outside the auto industry. Later in the day, it confirmed that Susan Docherty, currently general manager of Buick-GMC, will replace him.

LaNeve, 50, had served as vice president of vehicle sales, service and marketing for GM since 2005. As part of its reorganization following Chapter 11 bankruptcy proceedings, GM handed over marketing duties to Vice Chairman Bob Lutz in July.

GM's U.S. sales plunged 36 percent during the first nine months of 2009 compared with the same period last year. Total industry sales have fallen 27 percent over that period.

Docherty, 46, "brings a fresh perspective to the job and she has an extraordinarily high level of energy,” GM CEO Fritz Henderson said in an interview with Automotive News.