Home and auto lender GMAC Financial Services says it lost $5 billion in the last three months of the year, as losses from its mortgage operations kept the company in the red for another quarter.

GMAC is still working to sell its ResCap home lending division. The unit alone lost more than $4 billion during the quarter. GMAC also took a $3.3 billion charge related to its efforts to sell the unit.

GMAC's fourth-quarter loss compares with a profit of $7.5 billion in the same quarter last year.

The federal government has poured $16.3 billion into GMAC to keep it afloat and is now its majority owner. The lender has been battered by the downturn in the housing market.