Fannie Mae and Freddie Mac, the government-sponsored mortgage finance companies, will be allowed to buy loans worth as much as $729,750 for loans made between July 31, 2007 and Dec. 31, 2008, an increase over the current $417,000 loan limit, a move that could help struggling homeowners to refinance large mortgages at a lower interest rate. It will also allow the Federal Housing Administration to insure loans as high as $729,750 in expensive markets for loans made between July 31, 2007 and Dec. 31, 2008, an increase over the current $417,000 loan limit, a move that could help struggling homeowners to refinance large mortgages at a lower interest rate. It will also allow the Federal Housing Administration to insure loans as high as $729,750 in expensive markets