The head of the federal agency, James B. Lockhart III, that controls Fannie Mae and Freddie Mac is stepping down.

Lockhart, 63, the director of the Federal Housing Finance Agency, helped orchestrate the takeover of Fannie Mae and Freddie Mac last September as the financial crisis worsened and his agency, working with the Treasury Department, determined the companies were unstable and posed a serious risk to the global financial system.

The timing of James Lockhart's departure from the Federal Housing Finance Agency is not yet certain and a successor has not yet been named, according to an administration official who spoke on condition of anonymity, the Associated Press reported.