NEW YORK, Dec 15 (Reuters) - Fannie Mae said on Monday it will allow tenants to remain in their homes and avoid eviction even if the building's landlord goes into foreclosure.

Fannie Mae, the government-controlled U.S. mortgage finance company, said it now plans to sign new leases with rent-paying tenants living in the single- and multi-family foreclosed dwellings owned by the company.

The leases are likely to be short-term as Fannie Mae continues to market the properties for sale.

Foreclosures are at an all-time high and many economists, as well as the Mortgage Bankers Association, expect them to mount along with unemployment.

As of the end of September, Fannie Mae owned about 67,500 properties in foreclosure, according to Brian Faith, Fannie Mae spokesman. Up to 4,000 tenants are living in foreclosed dwellings owned by the company, he said.

The company previously said it would not evict tenants during the year-end holiday season.

Despite that pledge, Fannie Mae (FNM.P: Quote, Profile, Research, Stock Buzz) (FNM.N: Quote, Profile, Research, Stock Buzz) came under pressure from a legal-aid group that threatened to sue over recent evictions in Connecticut, the Wall Street Journal reported in its electronic edition on Sunday.

The company also would ensure that its holiday moratorium on new evictions was being followed until the new policy becomes effective in January.

"For tenants who would prefer not to enter into a lease, we will continue to offer monetary support for the transition to a new residence as an alternative option," Faith said in a separate statement.

The company's tenant eviction and foreclosure sale suspension is in place until January 9. It estimates 7,000 to 10,000 families have been able to stay in their homes because of this policy.

Freddie Mac, the second largest U.S. home funding company that also came under government control in September, is working on similar options that it expects to start rolling out in January, according to company spokesman Brad German.

A "Streamlined Modification Program" at both Fannie Mae and Freddie Mac (FRE.P: Quote, Profile, Research, Stock Buzz) (FRE.N: Quote, Profile, Research, Stock Buzz) announced last month also aims for earlier loan servicer intervention with borrowers who are late with mortgage payments and at risk of default. (Reporting by Lynn Adler and Jessica Hall, Editing by Chizu Nomiyama)