Fannie Mae and Freddie Mac, the US government-chartered mortgage financiers, could each raise up to $10bn of new capital as part of an agreement that allows them to buy and guarantee more mortgages, their regulator said on Friday.

James Lockhart, head of the Office of Federal Housing Enterprise Oversight (OFHEO), said in an interview on CNBC: “We allowed them greater freedom in response to them agreeing to raise several billion dollars of new capital, in the range of $5bn-$10bn each.”