Fannie Mae and Freddie Mac, the mortgage companies operating under U.S. conservatorship, will require additional government aid amid losses stemming from the 2008 credit crisis, the nation's top housing regulator said in its annual report to Congress. "While critical to supporting the ongoing functioning of the nation's housing finance system, the enterprises would be unable to serve the mortgage market in the absence of the ongoing financial support," said Edward DeMarco, acting director of the Federal Housing Finance Agency…