By Andrew Ackerman

WASHINGTON -- Mortgage giants Fannie Mae and Freddie Mac said they had hired major Wall Street firms to advise them on raising fresh capital as they move to exit government control.

On Monday Fannie said it had tapped Morgan Stanley, and Freddie said it had hired JPMorgan Chase & Co. The moves are the latest in the yearslong effort to return the mortgage companies to private ownership after they were bailed out by the government during the financial crisis.

The firms' independent federal regulator, the Federal Housing Finance Agency, hired its own adviser, the investment bank Houlihan Lokey, in February. Fannie and Freddie back about half of the $11 trillion U.S. mortgage market and are central to the widespread availability of the popular 30-year, fixed-rate mortgage.

Write to Andrew Ackerman at andrew.ackerman@wsj.com