The exit of Apple iOS software chief Scott Forstall was apparently anything but quiet. Forstall was forced out after he refused to sign a letter apologizing for problems with Apple Maps, according to the Wall Street Journal.

The New York Times confirmed the firing, along with the unrelated ouster of Apple’s new retail chief, John Browett.

The Journal reported that some within Apple considered Forstall a divisive figure who “never fit into the culture at Apple,” and who had long rankled other company execs but enjoyed the confidence of Steve Jobs. As WSJ reporter Jessica Lessin wrote:

Mr. Forstall’s departure came after mounting tension with members of Apple’s executive ranks. For years, senior executives had complained that he wasn’t cooperative and showed off his close relationship with Mr. Jobs.

In fact, Forstall recently sent an email to some of the folks on Apple’s iOS software team saying that the group “wasn’t working on enough big ideas in mobile software,” according to the WSJ. That’s effectively saying that Forstall thought the company was struggling to compete, so it’s no surprise that tensions were mounting.

Apple has said that Forstall will be replaced by Craig Federighi in 2013. Federighi will oversee both the iOS and OS X groups under one umbrella.