Nationstar Mortgage Holdings (NSM) bought $10.4 billion in mortgage servicing rights from Bank of America (BAC).

The portfolio is made up of Fannie Mae and Freddie Mac mortgages. Nationstar funded a portion of the purchase from a 65% co-investment from Newcastle Investment Corp. The loans are expected to transfer to the Texas servicer in July.

BofA serviced $1.3 billion in loans for investors as of March 31, down from $1.6 billion one year ago, according to its first-quarter financial filing. It handled 20% of the Fannie Mae single-family portfolio, making it the largest GSE servicer in the U.S., but that share dropped steadily from 26% in December 2010, according to Fannie Mae filings.

Nationstar will become the largest nonbank mortgage servicer in the country this year when its largest deals close. It made many acquisitions from firms looking to shrink their portfolios or exit the business altogether.

Nationstar agreed to purchase $201 billion in MSRs from the bankrupt Residential Capital last month. The deal is pending court approval. It also acquired $63 billion in servicing assets from Aurora Bank in March.

It bought a reverse mortgage-servicing portfolio from MetLife (MET) in April.

Nationstar went public in March, raising $233 million through an initial public offering. Its parent company Fortress Investment Group still controls more than 80% of the firm.

Should the ResCap deal go through, Nationstar will service mortgages held by more than 3.4 million borrowers.

Nationstar CEO Jay Bray said at a Keefe, Bruyette, and Woods conference Tuesday, the firm is not done acquiring new servicing.

"I think you'll see more of that to come," Bray said.