U.S. auto sales in the third quarter were the best in eight years, but mixed September results from leading automakers on Wednesday indicated the industry's torrid summer pace is slowing.

General Motors Co, Fiat SpA's Chrysler Group, Toyota Motor Corp, Honda Motor Co, Nissan Motor Co and Hyundai Motor Co all reported year-to-year sales gains on Wednesday, but Ford Motor Co said sales fell slightly from a year ago. And while Toyota's and Honda's sales were up, both companies missed analysts' forecasts.

A Reuters survey of nine analysts showed expectations for a 10 percent rise in September to about 1.25 million vehicles, with sales during the month at an annualized rate of 16.7 million, well below the 17.5 million pace as in August.

"The rate of growth in industry sales is beginning to moderate," Ford chief economist Emily Kolinski Morris said on a conference call. "We are getting closer to what would be a likely plateau in terms of the industry sales pace."

Ford sales fell 3 percent, to 180,175, as the automaker slowed production of the F-150 pickup truck, the best-selling vehicle in America, to prepare for the launch of the redesigned 2015 model. Analysts surveyed by Reuters expected a similar decline.

F-150 sales dipped 1 percent, with Ford's small cars and crossovers showing bigger declines. Ford's Lincoln brand jumped 13 percent, bolstered by the new MKC compact crossover.

GM sales increased 19 percent, to 223,437, about what analysts predicted. The automaker's full-size Chevrolet Silverado and GMC Sierra pickups soared 47 percent to 66,939. GM's premium Cadillac brand was flat.

Chrysler said sales rose 19 percent, to 169,890. Analysts expected a 17 percent rise. Its Jeep and Ram brands were up 47 percent and 35 percent, respectively, but sales of Jeep Grand Cherokee fell 14 percent.

Toyota sales increased 2 percent, to 167,279, but analysts had forecast a 7 percent gain. The company said SUVs and crossovers helped to drive its results.

Honda sales were up 7 percent, to 118,223, versus analysts' expectations of a 15 percent hike. The mid-size Accord sedan helped drive sales, with a 25 percent gain, but Civic sales dropped 7 percent.

Nissan sales climbed 19 percent, to 102,955. Analysts looked for a 15 percent increase. The company's premium Infiniti brand fell 13 percent, while sales of the Nissan Leaf electric car jumped 48 percent.

Some analysts were concerned that generous consumer deals, including low lease rates and zero-percent financing, are stealing demand from the future.

Each month, auto sales are an early indicator of U.S. consumer demand, particularly for large-ticket items.

On Tuesday, reports showed U.S. consumer confidence fell in September for the first time in five months, and home prices in July rose less than expected from a year earlier, underscoring the unsteady nature of U.S. economic growth.

GM shares were up nearly 3 percent on Wednesday after the company said it expects in 2016 to make its first profit in Europe in more than a decade. Ford shares were down 1.2 percent at $14.61.