DETROIT (AP) — Ford's leaders have watched Mark Fields, a brash Harvard MBA, turn the company's North American business into a profit machine. Now the CEO job is his to lose.

Fields, who has spent seven years as head of Ford's Americas division, will become chief operating officer on Dec. 1. He will report to CEO Alan Mulally, 67, who said Thursday that he plans to remain CEO at least through 2014.

Fields, 51, will lead day-to-day operations and head up the company's weekly business reviews with senior leadership. All of the company's business units will report to him.

The announcement puts to rest — for now — the swirl of speculation about Ford's succession plans. The sunny, charismatic Mulally will lead the company's long-term strategy and mentor the new leadership team.

Standard and Poor's Investors Service reiterated its "buy" rating on Ford's shares, saying the plan should reassure investors because Mulally will stay on.

Fields, though, has been a big player in Ford's return from near-collapse. Executive Chairman Bill Ford said Fields has managed the transformation of the company's North American operations, which were losing billions of dollars when Fields took over that key region in October 2005. The company closed plants, laid off thousands of workers, streamlined its vehicle development process and introduced strong new vehicles like the Explorer and Fusion. Earlier this week, Ford reported a record $2.3 billion pretax profit in North America.

"I put Mark in that job seven years ago. The growth that we've all seen in him has been remarkable," Bill Ford said.

Ford's board decided on the leadership changes at its regular meeting Oct. 19. Bill Ford stopped short of saying Fields would definitely be named CEO when Mulally retires, but he did say he would prefer Ford's next CEO to come from inside the company.

"I always look at talent, not only internally but externally. But I'm very happy with the team we've put together," he said.

Joe Hinrichs, who is now head of Asia Pacific and Africa, will replace Fields as head of the Americas. Hinrichs, 45, who ran Ford's manufacturing operations before taking over Asia, has also been frequently mentioned as a successor to Mulally.

David Schoch, currently chairman of Ford China, will become head of the Asia Pacific region.

Stephen Odell, group vice president of Europe, was named executive vice president and president of Europe, Middle East and Africa. He also was among the candidates to succeed Mulally.

Jim Farley, who is currently head of global marketing, will also become the head of Ford's luxury Lincoln brand. Lincoln has been struggling in recent years, and Ford is trying to revive it with new products. It's also introducing Lincoln to China in 2014.

Ford hasn't had a COO since 2006, when former President and COO Jim Padilla retired. Mulally said he has never worked with a COO, either at Ford or at Boeing Co., where he spent 36 years before coming to Ford.

"I'm really looking forward to nurturing Mark and supporting this team," Mulally said.

Mulally is highly respected at Ford for saving the company from financial collapse. Shortly after Bill Ford hired him in 2006, he mortgaged all of Ford's assets for a $23.5 billion loan, paid for a restructuring and helped keep Ford out of bankruptcy protection. Ford reported its best-ever third quarter pretax profit of $2.2 billion earlier this week.

"We not only survived but we have created a company that is healthy and is growing and has a clear vision for the future," Mulally said in a phone call with analysts and media.