DETROIT — The chief financial officer who guided General Motors to its first profitable year since 2004 and led its successful return to the stock market is leaving after being passed over for the top job.

Chris Liddell will step down April 1 after just 15 months at GM. He'll be replaced by treasurer Dan Ammann, a former Wall Street banker, the company said in a surprise announcement Thursday.

Liddell, 52, a former CFO at Microsoft, was once considered a candidate to succeed chief executive Ed Whitacre. But GM's board instead picked current chairman and CEO Dan Akerson when Whitacre made a surprise exit in August.

The move is the latest executive shake-up at GM, which emerged from bankruptcy protection in July of 2009. The company has had four CEOs in less than two years and an equal number of CFOs. Within the past year it has changed top executives in marketing, product development and other areas.

DALLAS — American Airlines is raising U.S. base fares $10 per round trip.If the increase sticks, it would be the seventh broad price hike this year by U.S. airlines, which say they need more revenue to offset rising fuel prices.United, Continental, US Airways and low-cost carriers JetBlue and AirTran, said they had not raised prices. Southwest did not immediately comment.American's latest fare increase also extended to Hawaii and Canada.