An affiliate of Liberty Property Trust (NYSE: LPT) has sold a mid-block office building in downtown D.C. for about $1 million less than it paid for the property in 2005 as the suburban Philadelphia firm prepares to be acquired by Prologis Inc. (NYSE: PLD). Liberty sold 1425 New York Ave. NW for about $47.45 million to an affiliate of Monument Realty, per documents filed Jan. 28 with the D.C. Recorder of Deeds. The fully vacant building, which Liberty acquired for about $48.48 million in 2005, is...