General Motors Co
Liddell, 52, who joined GM last year from software giant Microsoft Corp
He saw GM through its record initial public stock offering last November, after the company emerged from a government-sponsored bankruptcy. Replacing him is former Morgan Stanley
I came to General Motors to be part of something great, Liddell said in a statement. My objective was to help rebuild this iconic company.
A native of New Zealand, Liddell left Microsoft, where he was CFO, in November 2009 to look for a bigger job. When he joined GM, he was seen as a well-regarded outsider who could possibly succeed then-Chief Executive Officer Ed Whitacre when he stepped aside.
Microsoft said when Liddell left that he was looking at opportunities to expand his career beyond being a CFO.
However, GM named Dan Akerson, 62, as CEO last August, immediately leading to industry speculation that Liddell would eventually leave.
The decision to leave was Chris's, GM spokeswoman Lori Arpin said. He came here to be CFO and with the company on proper footing, he decided that it was the right time personally and professionally to pursue other opportunities. He has not announced his future plans yet.
Akerson said Liddell was a major contributor during a pivotal time in the company's history, guiding the IPO process and running finances.
Ammann joined GM in March 2010. His successor in the treasurer's office will be announced at a later date.
GM said Ammann, 38, had played a major role in key financial decisions at the company, including setting financial strategy and reducing debt, and working toward the IPO.
Prior to GM, Ammann was managing director and head of industrials investment banking at Morgan Stanley.
(Additional reporting by Bernie Woodall; Editing by Lisa Von Ahn, Dave Zimmerman)