the largest U.S. residential mortgage funds provider, on Monday asked the government for an additional $8.4 billion after the company lost $13.1 billion in the first quarter.

Including the latest request, Fannie Mae will have received more than $84.6 billion from the government, and the firm said it saw no end in sight to federal assistance.

The announcement comes less than a week after smaller mortgage finance company Freddie Mac, said it would need $10.6 billion in government funds after losing $8 billion in the first quarter.

The U.S. Treasurytook control of the two entities at the height of the financial crisis in 2008 as mortgage losses mounted. The two firms have now tapped more than $145 billion in assistance from Uncle Sam's unlimited credit line.

Housing analyst Rajiv Setia of Barclays Capital said Fannie Mae is likely to draw another $40 billion to $50 billion from the government.

The plan to put them into conservatorship was meant to be temporary, but more than a year and a half later, Treasury Secretary Timothy Geithnerhas only just begun the process of figuring out how to overhaul the U.S. housing finance system.

The company warned of "significant uncertainty as to our long-term financial sustainability" as it expects the continued weak housing market to keep default rates and credit-related costs high. More from ABC News here.