Ocwen Financial (OCN) is buying mortgage servicing rights and related servicing advances from OneWest Bank in Pasadena, Calif., for $2.5 billion.

The Atlanta mortgage servicer said Thursday it would buy $78 billion in unpaid principal balances of mortgage servicing rights using a combination of cash and available credit.

The deal is expected to close in the second half of this year. The companies have agreed to a termination fee of $50 million in case it does not close, according to a securities filing.

The rights portfolio from OneWest, which was founded in 2009 by investors who bought assets from the failed IndyMac bank, would be the latest in a series of additions to Ocwen's servicing portfolio, which grew 377% in the first quarter from a year earlier, to $469 billion.

In December the company bought Homeward, another servicer, for roughly $766 million. Two months later Ocwen paid roughly $3 billion for mortgage servicing rights that belonged to Residential Capital, a former unit of Ally Financial. In April, Ocwen bought the balance of Ally's servicing portfolio.

For its part, the $25 billion-asset OneWest has considered a sale or public offering. The company is said to have had discussions this spring with New York Community Bancorp (NYCB) and other suitors about a possible sale. New York Community had reservations about the quality of OneWest's mortgage portfolio, Reuters has reported.