The Obama administration may be set to tap current Fannie Mae (FNM) CEO Herb Allison as the next head of the government's $700bn Troubled Asset Relief Program, leaving both Fannie Mae and sister GSE Freddie Mac (FRE) searching for new chief executives. Freddie CEO David Moffett announced his resignation last month. Allison is set to replace Neel Kashkari as assistant secretary for the Office of Financial Stability as early as the end of this week, a report in the Wall Street Journal said Monday evening, citing unnamed sources. For Allison, the move might actually put him in a position facing far less scrutiny than his current role, even if he must defend a largely-unpopular program; both Allison and Moffett were installed as chief executives at the GSEs after the government placed both mortgage finance giants into conservatorship last year. Treasury secretary Timothy Geithner has been searching for months for someone to run TARP, but has seen senior posts become increasingly tough to fill, as candidates withdraw or don't pass muster in the vetting process. Last month, hedge-fund manager Frank Brosens -- largely expected to take Kashkari's now-temporary role -- withdrew for what has only been described as "personal reasons." Allison, 65, is the former chairman of investment company TIAA-CREF and was a longtime Merrill Lynch & Co. executive. If nominated for the Treasury role, he must be confirmed by Congress. Write to Paul Jackson at Disclosure: The author held no relevant investment positions when this story was published. Indirect holdings may exist via mutual fund investments.