Sales of new U.S. single-family homes plunged to the slowest pace on record in July, the government said Wednesday in a report. The Commerce Department said sales of single-family homes fell 12.4 percent last month to a 276,000-unit annual rate, down from a rate of 315,000 in June. July's pace was the slowest on records dating from 1963, and the median new-home sale price fell to its lowest level since late 2003. Collectively, the past three months have been the worst on record for sales of new homes. Weakness in home sales was intensified by the ending of a popular housing tax credit for buyers that had helped to previously increase sales.