Anworth Mortgage Asset Corp. said Tuesday that it plans to sell 11 million common shares to raise money to buy more mortgage debt, sending shares up more than 4 percent in trading.

Anworth said it plans to reap as much as $103 million if all options are exercised and will use the proceeds to buy bonds backed by mortgage debt.

Anworth owns a $4.1 billion portfolio of mortgage-backed bonds issued by government-sponsored agencies like Fannie Mae and Freddie Mac. The company lost $154 million in the first nine months of 2007 because bonds secured by mortgage debt lost value.

Shares in Anworth rose 4.6 percent to $8.96 in afternoon trading Tuesday on the New York Stock Exchange.