The trustee for bankrupt U.S. mortgage lender Thornburg Mortgage Inc gained court approval on Friday to auction the company's $11 billion mortgage servicing portfolio early next year.

Judge Duncan Keir of the U.S. Bankruptcy Court in Baltimore signed a court order on Friday, allowing the sale to go forward at an expedited pace.

Thornburg, once one of the leading providers of jumbo residential mortgages with some $24.4 billion of assets, became one of the biggest casualties of the subprime housing crisis when it filed for bankruptcy in May.

Since then, the company has continued to service a residential mortgage loan portfolio with a balance of about $11 billion, but has not originated, purchased or securitized any other residential mortgage loans, according to court papers.

The sale of Thornburg's once-prized servicing portfolio would represent a major milestone in its liquidation process, which has been run by a trustee since October.

According to court papers, Thornburg's trustee will accept bids for the servicing portfolio in January. Judge Keir has set a court hearing to approve the sale to the highest bidder for February 10.

The trustee, Joel Sher, was appointed in October to take over the liquidation of Thornburg, which now goes by the name of TMST Inc, after it was discovered that former executives were using staff and equipment to launch a start-up venture.

In court papers, the trustee said a sale was necessary because the servicing portfolio was subject to market risk, and would generally decline in value over time since the company is unable to add new mortgages to the portfolio.

The Trustee believes that a targeted sale process involving potential servicers of the Servicing Portfolio is most likely to achieve the highest and best price for the Servicing Portfolio, the trustee said in court papers earlier this month.

The case is In re: TMST Inc, U.S. Bankruptcy Court, District of Maryland, No. 09-17787.

(Reporting by Emily Chasan; Editing by Phil Berlowitz)