CIT Group Inc on Tuesday reported a $1 billion loss in the fourth quarter, excluding one-time items and accounting adjustments, as the recently-bankrupt commercial lender was hurt by high borrowing and credit costs.

The U.S. company said in a regulatory filing that it would not return to profitability in 2010 under regular accounting rules. But it added that new, post-bankruptcy accounting measures would bring it back into the black this year.

CIT, which last month named John Thain its new chief executive, reported net income of $3.2 billion in the fourth quarter under the post-bankruptcy accounting, known as Fresh Start Accounting, or FSA.

Shares of the company rose 2.2 percent to $37.10 in after-market trading.

CIT received $2.3 billion from the U.S. government's Troubled Asset Relief Program in December, 2008. That obligation was wiped out when it filed for bankruptcy in November; it emerged from bankruptcy the following month.

(Reporting by Jonathan Spicer; Editing by Bernard Orr)