WASHINGTON (Reuters) - Total sales at retailers in August fell for a second month in a row, according to a government report on Friday that showed consumers were coming under increasing pressure amid rising prices.

Sales dropped 0.3 percent in August to a seasonally adjusted $381.17 billion after a sharply revised 0.5 percent drop in July that previously was reported as only a 0.1 percent decline.

The August fall in sales was sharply contrary to forecasts by Wall Street analysts surveyed by Reuters who had expected a 0.2 percent sales increase.

Sales at motor vehicle dealers rose 1.9 percent in August -- the first increase since January -- after a 4.3 percent July drop. But August sales still were down 13.5 percent from a year earlier.

Excluding motor vehicles, retail sales in August were down 0.7 percent after gaining 0.3 percent in July.

Gasoline sales fell 2.5 percent last month - the biggest monthly decline since mid-2007 - after a 0.2 percent rise in July. Gasoline prices eased in August from record July levels.

Sales of building materials, clothing and electronics all were weaker in August than they were in July. Analysts have been warning that, with businesses cutting jobs in every month so far this year, consumers are bound to have difficulty keeping up spending that fuels two-thirds of national economic activity.