Flagstar Bancorp Inc., one of the top sellers of mortgages to Fannie Mae and Freddie Mac, recently concluded a final $50 million investment by private equity firm MP Thrift Investments L.P., an entity formed by MP (Thrift) Global Partners III LLC. The transaction between Flagstar and MP Thrift Investments L.P., also known as MatlinPatterson, is part of a recent trend of PE firms...