Large banks and some smaller shops continue to test the servicing sales market this fall, with bulk offerings from Citigroup and Flagstar garnering attention from investors. Industry advisors who track the market say Flagstar recently wrapped up bidding on a $12 billion package of mortgage servicing rights on newly originated loans. These were pristine quality receivables, stuff that was funded over the past few months, said one observer who saw the bid package. This summer, Flagstar in an effort to capture the value of MSRs held on its balance sheet sold...