• by Karl Greenberg , December 10, 2009

Who's next? The latest departure at General Motors -- Brent Dewar, long-time marketer general manager of the Chevrolet division -- follows a shakeup by Chairman Ed Whitacre that included jettisoning CEO Fritz Henderson, replacing Robert Lutz former head of marketing with former Buick-GMC chief Susan Docherty, who is now GM's VP of sales, service and marketing.

Dewar, who was not offered the top sales job Docherty now has, is leaving in April "to dedicate more time to his family and to pursue personal interests," per the company.

As part of a corporate revamp post-bankruptcy, Dewar -- who is 54 -- was tapped in July to head up the Chevrolet division, which in the new GM is intended to be the cornerstone and volume brand in the portfolio comprising GMC, Buick, Chevrolet and Cadillac. Saab, Hummer, Pontiac and Saturn are all either being shuttered or on the block.

The specifics are that Dewar, VP global Chevrolet, has been replaced by James Campbell, formerly head of GM's Fleet and Commercial Operations. The company says Dewar will be on a "special assignment," supporting Mark Reuss, GM president North America, in his new role.

On Wednesday, Michael Richards, who last week was hired to be general manager of the Buick-GMC channel, was reportedly slated to do a webcast on GM's Fast Lane blog. Instead, he apparently quit. Brian Sweeney, general sales manager for Buick-GMC, will now head the division on an interim basis.

Things have been in radical flux at the company since the government appointed Whitacre to run it after Rick Wagoner, the former chairman and CEO, was forced out. Mark LaNeve, former VP of U.S. sales, left in October after the marketing half of his job went to Robert Lutz, who with the ascension of Docherty to a role that encompasses both sales and marketing oversight, was shifted to an advisory role. Docherty's move up in the corporate echelon has been a two-part shift, starting with her appointment as General Motors VP U.S. sales, in October.

She was moved into the sales, service and marketing leadership after Henderson was nudged out on Dec. 1. At least one analyst says the changes aren't over. "I would not be surprised if Lutz leaves," says Michelle Krebs of Edmunds.com.

"It's a washing machine now. There's tremendous turmoil with an interim CEO [Whitacre] who wants results and he is gong to put people in he thinks will bring them," says Krebs. "Certainly Dewar was close with Fritz Henderson, and I'm sure he was in competition with Docherty for the top marketing job. And nobody's position is safe right now. I think if you ask any of the top executives and managers at GM right now, they know nobody's job is safe."

She also points out that filling the holes left will be hard to do, because it is now difficult to lure people to Detroit. "That makes it that much more difficult."

Other changes at the automaker:

• Diana D. Tremblay was named VP, Manufacturing and Labor Relations. Tremblay was most recently vice president of Labor Relations.

• Denise C. Johnson, former vehicle line director and chief engineer for global small cars became became VP, Labor Relations.

• Nick Reilly was tapped for president, GM Europe. Reilly had been leading the restructuring efforts in Europe with the Opel/Vauxhall operations and will leave his role leading GM International Operations.

• General Motors named Tim Lee, former group VP, manufacturing and labor relations president of GM International Operations, overseeing GM's Asia-Pacific, Latin America, Africa, and Middle East operations.