Ford CEO Alan Mulally formally addressed several months of speculation and rumors on Tuesday, stating that he was no longer in the running for the top job at Microsoft. The firm's current CEO, Steve Ballmer, said he would retire by mid-2014, and Mr. Mulally had been considered the top candidate.

"I would like to end the Microsoft speculation because I have no other plans to do anything other than serve Ford," Mr. Mulally told the Associated Press. When pressed about his dedication to Ford, Mulally reiterated, "You don't have to worry about me leaving."

Mr. Mulally had been at the top of the candidates list for the Microsoft CEO position since Mr. Ballmer announced his surprising but drawn-out exit from the company in August. But although Ford has always denied that there was any possibility that Mulally would do anything other than live up to his previous commitments to that company, Mr. Mulally has been enticingly vague, fueling speculation that a deal would be made.

Ford's board of directors grew increasingly restless with the drama as 2013 drew to a close. In a December meeting, the board allegedly pressured Mr. Mulally into publicly addressing his plans, with one source noting that "people don't write about Mustang, they don't write about earnings, they write about Mulally." One might surmise that this week's announcement is the result of that discussion.

Despite Mulally's credentials—his successful strategy to turn around Ford will be studied for years to come—he was always a long shot. He's 68 years old, over a decade older than the man he'd replace at Microsoft, and he was previously planning to retire this year.

Related: "Microsoft Reports Progress in CEO Search"

As for Microsoft, the firm is widely rumored to be close to naming a new CEO, although questions remain about the roles Mr. Ballmer and cofounder Bill Gates—still Microsoft's chairman—will play going forward. Leading internal candidates for the job include Satya Nadella, who oversees Microsoft's server and cloud services businesses, and Tony Bates, who previously ran Skype.

As for now, however, Microsoft isn't talking. "Out of respect for the process and the potential candidates, we don't comment on individual names [for the CEO position]," a Microsoft spokesperson noted.