DETROIT/NEW YORK - Dan Akerson arrives at General Motors Co. as CEO with the same mandate given his predecessor just eight months ago: Bring new leadership to an automaker still struggling with the legacy of its government bailout, Reuters reported.

Akerson, 61, replaces Ed Whitacre as of September in an abrupt shake-up GM announced just a day before it had planned to file for a politically charged stock offering expected to be one of the largest ever.

The suddenness of Whitacre's departure -- coming just a day after a meeting of the top U.S. automaker's board and announced at an improvised teleconference for reporters and financial analysts -- stunned insiders.

GM's financial advisers, who had spent weeks preparing an IPO filing for U.S. securities regulators, scrambled to rewrite complicated paperwork to take Whitacre out and put Akerson in, one person with direct knowledge of the private process said.

Whitacre, who served as CEO at AT&T and steered it through a series of key mergers, remains GM chairman until the end of the year. He had been expected to quit after guiding GM through an IPO to reduce the U.S. government's 61 percent ownership stake.

Just a week ago, Whitacre, 68, said he had not given any thought to resigning. "Everybody knows at my age I'm not a real longtimer," he told reporters.

A lanky Texan who confessed to feeling lost in Detroit and commuted home by plane to San Antonio on weekends, Whitacre had become the face of GM's turnaround and starred in TV commercials meant to mark its return from bankruptcy.

At GM, Whitacre became famous for spurning the PowerPoint presentations that had become a symbol of the slow decision-making process at the 102-year-old automaker.

After GM's top executives were blasted for being out of touch and riding to their offices at Detroit's Renaissance Center on a private elevator, Whitacre took pains to mix with workers, showing up unannounced in offices and factories.

But Whitacre's hands-off style of delegating also left him appearing sometimes out of touch and at odds with the Obama administration, which wants to see a successful IPO as early as November.

Last week Whitacre said GM was weeks away from an IPO filing, a statement that puzzled staff who were almost finished with the needed work.

Akerson, a quiet and private executive, will face the pressure of becoming the face of GM in an industry where the CEO is often called on to be the biggest salesman.

Like Whitacre, Akerson had a long career in the tightly regulated telecommunications industry. He also has a history of dealmaking as head of buyouts at private equity firm The Carlyle Group.

Akerson became head of global buyouts at Carlyle last July, and was designated by the Treasury Department to serve on the GM board in July 2009 after the automaker emerged from its government-supported bankruptcy.

Analysts said Akerson heads off potential investor concern about executive succession.

A former U.S. Navy officer who served on a destroyer from 1970 to 1975, Akerson supported fellow Navy veteran and Republican John McCain for president.

In 2008, Akerson and his wife donated $80,800 to the Republican Party and its candidates, and nothing to the Democrats or now-President Barack Obama, according to the Center for Responsive Politics in Washington.

The Obama administration has repeatedly said that it chose its representatives on GM's board, including Akerson, for their qualifications without considering their politics.

Akerson lacks one quality analysts credit with giving Ford Motor Co. CEO Alan Mulally a leg up as an outsider -- experience in manufacturing.

Ford hired Mulally away from Boeing Co. in 2006 and as CEO, Mulally has been credited with leading a surprising turnaround of the No. 2 U.S. automaker.

But GM former Vice Chairman Bob Lutz, a legendary "car guy" in Detroit, said that lack of experience won't stop Akerson.

"Like many strong leaders, he has equally strong opinions," Lutz said, adding that he would have to listen to the new layer of management Whitacre has put in place. "If he can do that, GM will face a very bright future under his leadership."