The nation’s two largest residential mortgage funding companies, already under government conservatorship, may be asking for more money in the coming weeks, as loan delinquencies loom larger and the many subprime securities in their portfolios continue to suffer.

Freddie Mac made a regulatory filing Friday with the U.S. Treasury Department stating an intent to borrow another $30 billion to $35 billion in order to makeup for projected fourth quarter losses. Rival company Fannie Mae is likely to ask for $5 billion to $10 billion for similar efforts.

The two mortgage giants guarantee or hold almost half of all U.S. home loans and both were seized last September by the federal government. As both companies experienced deep portfolio losses and ultimately faced bankruptcy, the Treasury stepped in and established a conservatorship of each in order to save the already foundering mortgage market from a potentially crippling blow if either Fannie or Freddie went belly up.

Prior to the takeovers, both Fannie Mae and Freddie Mac were government sponsored entities, chartered by Congress to help provide money for increased homeownership but run by private interests.

Fannie and Freddie are perceived as being vital to the nation’s housing market, especially at this time as other sources of mortgage funding have contracted during the current credit crunch.

Freddie has seen greater losses  than Fannie in the latest quarter as its portfolio is stocked with more subprime mortgage backed securities. There are some analysts who believe that Fannie will be subject to more risk and loss through the current year as the value of mortgage securities is expected to drop further.

To date,  Freddie Mac has drawn out $14 billion of the $100 billion available from the Treasury. The newly requested funds for the company, based in McLean, Virginia, will be injected in the form of senior preferred stock.