"We increased our general provision for commercial loan losses this quarter in light of continuing stress in our commercial real estate portfolio," the company said.
CapitalSource, which transformed itself from a real estate investment trust to a bank in January, said net loss for the quarter was 87 cents a share, compared with a profit of $13.7 million, or 5 cents a share, last year.
Analysts on average expected a loss of 26 cents a share for the quarter, according to Thomson Reuters I/B/E/S.
Provision for loan losses rose to $221.4 million from $110.3 million, last year.
CapitalSource joins a host of other U.S. commercial banks that have seen their profits slip as they increase provision for bad loans amidst rising defaults.
Net investment income fell about 14 percent to $135.7 million.
Shares of the company closed at $3.56 Friday on the New York Stock Exchange.