FACTBOX: Key facts on Fannie Mae and Freddie Mac

NEW YORK (Reuters) - Shares in U.S. mortgage finance firms Fannie Mae and Freddie Mac plunged on Friday as market speculation mounted that the government was set to take them over to resolve their funding problems.

Investors have been dumping shares and buying the bonds of the government sponsored entities (GSEs) instead in anticipation that a state takeover would effectively give their combined outstanding $1.6 trillion in debt a clear government guarantee.

Fannie Mae and smaller sibling Freddie Mac own or guarantee almost half of all home loans in the United States. They face billions of dollars in losses and may need to raise massive amounts of new capital as the U.S. housing market faces its worst downturn since the Great Depression.

Here are some key facts about the two companies:

* FANNIE MAE:

-- Original name: Federal National Mortgage Association

-- Created in 1938 by Congress as part of a campaign aimed at expanding the secondary U.S. mortgage market and increasing home ownership and rental housing.

-- Assets: $843.23 billion (March 31, 2008)

-- Liabilities: $804.23 billion (March 31, 2008)