GMAC Financial Services, a lender that has received more than $16 billion from the U.S. government across multiple bailouts, said it lost $5 billion in the fourth quarter after writing down bad mortgage assets.

GMAC, one of the largest car loan makers in the United States, said in December that it did not expect to record more major losses from its mortgage unit. Home loans fueled GMAC's growth earlier this decade but have since triggered billions of dollars of losses for the company.

The fourth-quarter loss compares with net income of $7.5 billion in the fourth quarter of 2008.

(Reporting by Dan Wilchins; editing by John Wallace)