WASHINGTON (Reuters) - Fannie Mae and Freddie Mac, two government-controlled housing finance agencies, would need a big cash injection to weather another financial meltdown, a government regulator said on Monday.

Fannie and Freddie would need as much as $126 billion in taxpayer funds to come through a serious downturn, according to a 'stress test' from the Federal Housing Finance Agency.

The companies, which were once owned by shareholders, have drawn $187 billion from the U.S. Treasury since they were seized by the government in September 2008 as the global financial crisis tightened.

Since then, as the housing market has strengthened, they have returned roughly $250 billion to the Treasury.

Lawmakers have not settled on the future of two companies.

The 'stress test' required by the Dodd Frank reform legislation of 2010 projected the companies would have to draw at least $49 billion to $126 billion in the case of a serious economic downturn.

(Reporting by Patrick Rucker; Editing by Dan Grebler)