NEW YORK - UBS Real Estate Securities Inc., a creditor in the Chapter 11 bankruptcy of Residential Capital LLC (ResCap), on Feb. 13 filed a brief in the U.S. Bankruptcy Court for the Southern District of New York, arguing that it has a valid claim against the bankruptcy estate for $56,451,603 (In Re: Residential Capital LLC, No. 12-12020, Chapter 11, S.D. N.Y. Bkcy.).