Speaking at the Ira Sohn conference earlier today and then on CNBC later, activist investor Bill Ackman has finally opened up on his thoughts about Fannie Mae / Federal National Mortgage Assctn Fnni Me (OTCBB:FNMA) and Freddie Mac / Federal Home Loan Mortgage Corp (OTCBB:FMCC). At issue is lawmakers’ attempts to wind down both firms and replace them with some kind of alternative.

Bill Ackman Fannie Mae

Bill Ackman on Fannie Mae, Freddie Mac on CNBC

Today on CNBC, Ackman reportedly said private companies would take a hundred years to be able to reach the size and capital levels of Fannie Mae / Federal National Mortgage Assctn Fnni Me (OTCBB:FNMA) and Freddie Mac / Federal Home Loan Mortgage Corp (OTCBB:FMCC). He also said both government-sponsored entities have “very valuable” brand names.

Ackman said he wants to take both firms back to the way they were before—”a low-risk business so long as they stay away from sub-prime.” U.S. taxpayers bailed out both Fannie Mae / Federal National Mortgage Assctn Fnni Me (OTCBB:FNMA) and Freddie Mac / Federal Home Loan Mortgage Corp (OTCBB:FMCC) in the wake of the subprime mortgage crisis. Ackman thinks there’s no alternative to the firms in the U.S. housing market.

Ackman at Ira Sohn Conference

Bill Ackman’s appearance on CNBC was literally right after he spoke at the Ira Sohn conference. He said at the conference that Fannie Mae / Federal National Mortgage Assctn Fnni Me (OTCBB:FNMA) and Freddie Mac / Federal Home Loan Mortgage Corp (OTCBB:FMCC) have “enabled a very strong housing market apart from the bubble and the bubble bursting.” Ackman believes the two firms don’t have many competitors in the market.

Lawmakers have proposed private versions of Fannie Mae / Federal National Mortgage Assctn Fnni Me (OTCBB:FNMA) and Freddie Mac / Federal Home Loan Mortgage Corp (OTCBB:FMCC). Unfortunately, however, those firms would have to raise up to $500 billion in order to become fully capitalized, according to Ackman. He thinks this is unlikely though, joining others who have criticized the U.S. government for essentially stealing Fannie Mae’s and Freddie Mac’s dividends.

Ackman doesn’t think anyone “of any consequence” would invest in the new versions of the firms. However, last month Warren Buffett said he would consider investing in their successors.