US auto sales offered a mixed picture in November, with Ford reporting an increase but GM and Fiat Chrysler posting declines, according to monthly sales data released Friday.

Ford's 6.7 percent sales increase compared with November 2016 was driven by solid jumps in sport utility vehicles and trucks -- including the best showing for the market-leading F-Series truck since 2000 -- as well as higher sales of sedans.

Total sales at the US number-two automaker came in at 210,771 vehicles, slightly better than the forecast by Edmunds.

But at GM, sales fell to 245,387 vehicles, down 2.9 percent and falling far short of Edmunds' forecast for a 1.8 percent gain.

GM said retail sales were flat compared with the year-ago period, but cited the much lower deliveries to rental companies as the main reason for the drop in overall performance.

Sales of many larger "crossover" vehicles increased, however, and the biggest US carmaker said it was optimistic that an improving US economy would keep consumption high.

"US economic growth has stepped up and we expect the momentum will carry over to 2018," said GM chief economist Mustafa Mohatarem.

"Employment continues to grow at a solid pace, wage growth will accelerate and consumer confidence just hit a 17-year high, so industry sales should remain strong."

At FCA, retail sales rose two percent, but as with GM, its overall results were hit by a decline in sales to rental companies. Total sales dropped four percent to 154,919 vehicles, a bit below the Edmunds projection.

After a multi-year boom in auto sales, carmakers had expected the market to slow down in 2017 compared with the record-setting 2016.

While sales this year are on track to decline, the performance has been boosted by a strengthening economy and the unexpected lift from back-to-back US hurricanes that boosted sales of replacement vehicles in September and October.

Edmunds is projecting that total sales will come in at 17.2 million for 2017, down from 17.55 million last year.