Robert Weisz’s RPW Group locked in a $240 million loan from Blackstone Group and SL Green Realty to purchase the 44-story office tower at 275 Madison Avenue in Midtown, sources told The Real Deal. The Westchester County-based landlord closed Friday on the $270 million purchase of the landmarked 336,000-square-foot tower at East 40th Street, the firm said. It entered contract to buy the property from Aby Rosen’s RFR Holding in June, as TRD first reported.