The $5 trillion market for U.S. agency mortgage-backed securities should be able to weather the scheduled end of Federal Reserve purchases as value-seeking investors fill the void, a Freddie Mac executive said on Monday. Those investors could include Freddie Mac, which has room to increase its $755 billion portfolio, Mike Dawson, a vice president of deal and contract management at Freddie Mac, told reporters at an American Securitization Forum conference. "I don't see huge changes out there other than a little spread widening," he said, referring to yields on MBS relative to benchmark securities. The spread affects rates that lenders offer to consumers who are trying to snap back from the economic recession and housing slump.