WASHINGTON (Reuters) -Sales of previously owned U.S. homes increased solidly in August as lower mortgage rates pulled buyers back into the market, though a softening labor market could curb further gains. "Lower mortgage rates are enabling more homebuyers to go under contract," said Lawrence Yun, the NAR's chief economist. Mortgage rates declined in August as the Federal Reserve prepared to resume easing monetary policy. The rate on the popular 30-year mortgage is near an 11-month low, data from mortgage finance agency Freddie Mac showed. But some of the stimulus from low mortgage rates could be offset by a weakening labor market.