Fed to start buying mortgage-backed securities

WASHINGTON -- The Federal Reserve says it will begin purchasing up to $500 billion in mortgage-backed securities early next month in an effort to bolster the U.S. housing market.

The Fed first announced the purchases in late November, but did not say when they would begin. The central bank says it will purchase securities that are guaranteed by home loan giants Fannie Mae, Freddie Mac and Ginnie Mae.

The Fed also says BlackRock, Goldman Sachs Asset Management, PIMCO and Wellington Management Company will operate the program.