When Chris Liddell announced his departure from Microsoft, the word from the company was that he wanted to expand his career beyond the role of chief financial officer. As it turns out, he's remaining a CFO, in what promises to be a considerably more challenging position. Automotive giant General Motors named Liddell its new chief financial officer this morning.

"Chris brings a depth and experience to this job that were unmatched in our search for a new financial leader," said Ed Whitacre, GM chairman and CEO, in the news release. "Chris will lead our financial and accounting operations on a global basis and will report directly to me. We're also looking to his experience and insights in corporate strategy as a member of the senior leadership team in helping our restructuring efforts."

There are no doubt some fun conversations taking place between Liddell and Microsoft CEO Steve Ballmer, who is a tried-and-true Ford guy, dating back to his dad's time working at the automaker.

Update: Here's a financial breakdown illustrating the differences in the companies' finances: GM reported (PDF) a $1.2 billion loss on $26.4 billion in revenue in the quarter ended Sept. 30. Microsoft, obviously in a completely different business, posted $3.6 billion in profits on $12.9 billion in revenue during roughly the same period.

Liddell was known for significantly reducing Microsoft's operating expenses during his tenure at the company, and that no doubt played a role in his appointment as finance chief for the struggling automaker.

And as a final note, it will be interesting to see if the hiring of Liddell creates stronger ties between Microsoft and GM. As we've reported previously, the auto company's use of OnStar wouldn't necessarily preclude it from adopting Microsoft's technology for connecting to phones and portable devices in cars. Ford has been Microsoft's flagship partner on that technology, with its Sync system, but Ford CEO Alan Mulally has said the pact would now let Microsoft work with other U.S. automakers, as well.