Fannie Mae and Freddie Mac, the two biggest providers of financing for U.S. home loans, fell to the lowest levels in 17 years in New York trading after a former Federal Reserve president said the companies may need a government rescue. ...Fannie Mae tumbled as much as 24 percent and Freddie Mac slumped as much as 34 percent in New York Stock Exchange composite trading after UBS AG analysts said in a report today that Freddie Mac's decline creates ``challenges'' for the company's plan to raise $5.5 billion. ...Chances are increasing that the U.S. will bail out Fannie Mae and Freddie Mac because they don't have enough capital to weather the worst housing slump since the Great Depression, former St. Louis Federal Reserve President William Poole said in an interview. Freddie Mac owed $5.2 billion more than its assets were worth in the first quarter, making it insolvent under fair value accounting rules. The fair value of Fannie Mae assets fell 66 percent to $12.2 billion, data provided by the Washington- based company show, and may be negative next quarter, Poole said. ...``Congress ought to recognize that these firms are insolvent, that it is allowing these firms to continue to exist as bastions of privilege, financed by the taxpayer,'' Poole, 71, who left the Fed in March, said in the interview yesterday. ...Poole roiled markets in 2003 when he said the government should consider severing its implied backing of Fannie Mae and Freddie Mac and the companies lack the capital to weather financial market disruptions. In 2006 and 2007 he called for lawmakers to strip Fannie Mae and Freddie Mac of their charters.