Newcastle Investment Corp., a behind-the-scenes player in Nationstar’s recent purchase of $215 billion of servicing rights from Bank of America, plans to spin off part of its business into a new unit called New Residential Investment Corp. According to a filing with the Securities and Exchange Commission, NRIC will invest in MBS, excess mortgage servicing rights, nonperforming loans and other asset classes. The company hopes to complete the spin-off by the end of March. The shares, though, will be spun-off...