Nationstar Mortgage Holdings (NSM) announced it closed on the purchase of mortgage servicing rights with an approximate $8.5 billion unpaid principal balance from a top-four financial institution, adding to its recent rapid growth.

This servicing portfolio consists of rights to service loans that are owned, insured or guaranteed by a GSE.

“We are pleased to have completed this acquisition and welcome our new customers to the Nationstar family. We are confident that we will be able to provide these customers with an exceptional customer experience and look forward to offering solutions that will increase mortgage affordability and preserve homeownership,” Nationstar CEO Jay Bray said.

“This acquisition is further evidence that we continue to work relentlessly with all stakeholders including customers, investors and regulators, to demonstrate our commitment to helping homeowners. Working side-by-side with customers and regulators will provide positive solutions for homeowners and improve portfolio performance for investors as we grow our servicing portfolio,” he added.

Nationstar has significantly increases its servicing portfolio since the end of the second quarter 2014, announcing the acquisition of $43 billion of servicing portfolios. Including this $8.5 billion portfolio, $37 billion has closed-to-date, with the remaining $6 billion expected to close by the end of the first quarter of 2015.

The nonbank servicer has had a lot of good press lately, with several analysts upgrading their ratings on the company.  

Most recently, FBR Capital Markets upgraded Nationstar to outperform from market perform based on expectations for continued portfolio and earnings growth.