General Motors Co's board of directors, citing a need to chart a new course, dismissed Chief Executive Fritz Henderson on Tuesday, a person with direct knowledge of the proceedings said.

GM Chairman Ed Whitacre will become interim chief executive as the automaker begins an immediate search for a replacement.

Henderson, a career GM executive, became CEO eight months ago, vowing to reform the slow-moving culture that contributed to the automaker's collapse. The announcement of his departure came after a meeting of GM's 13-member board in Detroit.

Henderson became CEO in March after his predecessor, Rick Wagoner, was forced out by the Obama administration as part of the U.S. government-funded restructuring of GM.

The board decided -- and Fritz agreed -- that given where we are, it was time to make some changes, GM spokesman Chris Preuss said at a hastily arranged news conference.

Whitacre, a former AT&T chief executive, became chairman of GM in July as part of a new board vetted by the U.S. Treasury and intended to safeguard the government's $50 billion investment in the automaker.

The U.S. government has a majority stake in GM, but the Obama administration has repeatedly said that it is leaving oversight of the company to Whitacre and the board.

Preuss said the White House had been notified of Henderson's departure, but was not part of the decision.

Whitacre appeared briefly before reporters at GM's headquarters in Detroit but did not take questions on why the board had chosen to part ways with Henderson.

Reading from a prepared statement, Whitacre said Henderson, who helped GM through its July bankruptcy, had done a remarkable job in leading the company through an unprecedented period of challenge and change.

While momentum has been building over the past several months, all involved agree that changes needed to be made, Whitacre said.

With the appointment of Whitacre, all three U.S. automakers are now headed by outsiders to Detroit.

Ford Motor Co CEO Alan Mulallly left Boeing Co in 2006. Chrysler is now headed by Fiat SpA CEO Sergio Marchionne.

(Reporting by David Bailey, writing by Kevin Krolicki; editing by Patrick Fitzgibbons and Matthew Lewis)

AT&T General motors