(Corrects in last paragraph to show truck sales were up at GM and Chrysler only, not Ford)
By Bernie Woodall and Ben Klayman
DETROIT, Sept 3 (Reuters) - U.S. August auto sales were unexpectedly strong, led by Ford Motor Co, Chrysler Group and Nissan Motor Co, which easily beat analysts' estimates as the industry is seen reaching volumes not seen since before the recession.
Ford sales were up 0.4 percent, while Chrysler, a unit of Fiat SpA, showed a 20 percent gain, the automakers reported on Wednesday. Nissan was up 11.5 percent. Analysts looked for gains of 11.8 percent for Chrysler and 2.8 percent for Nissan, and a decline of 1.9 percent for Ford.
General Motors Co said August sales fell 1.2 percent, narrowly missing expectations.
Chrysler forecast a stronger-than-expected month for the industry, up 3 percent, versus analysts' estimates of a rise of only 0.1 percent.
Auto sales are an early indicator of consumer demand as the industry accounts for one-fifth of all U.S. retail spending.
Analysts polled by Thomson Reuters expected monthly industry auto sales of about 1.5 million new vehicles, and a seasonally adjusted annualized sales rate of 16.6 million. It would be the sixth straight month showing an annualized rate above 16 million, a level reached only twice in 2013.
Research firm Edmunds.com pointed to two trends affecting August sales: A higher percentage of zero-interest loans and gas prices falling to their lowest in four years.
Incentive spending by the industry last month also climbed from a year ago, to an average $2,772 per vehicle, but declined slightly from July, according to research firm TrueCar.com. Virtually all major automakers except Nissan boosted discounts from a year ago.
Chrysler said U.S. Labor Day weekend sales were "tremendous," which helped to power the automaker to a 53rd consecutive month of year-on-year sales gains.
GM and Chrysler reported healthy gains in sales of full-size pickups, which provide the bulk of their profits. (Additional reporting and writing by Paul Lienert in Detroit; Editing by Jeffrey Benkoe)