General Motors Co's sales in October fell a less-than-forecast 1.7 percent as hefty gains for pickups and SUVs offset declines for its sedans but the industry was expected to report a larger drop.

U.S. auto sales in October were seen declining between 6 percent and 8 percent, according to industry analysts, as higher consumer discounts failed to prevent a fall-off from last year's record high.

GM said on Tuesday U.S. industry auto sales will be 17.4 million on a seasonally adjusted annualized rate, slightly weaker than most industry analysts expected.

GM's two full-size pickup truck models, Chevrolet Silverado and GMC Sierra, collectively fell 7.6 percent.

GM's Chevrolet Tahoe, Chevrolet Suburban and GMC Yukon large SUVs collectively gained 69 percent versus a year ago. The vehicles are hugely profitable for GM.

The rate of decline in October from a year ago will not be known until later this week because Ford Motor Co is delaying its sales report due to a fire at its Dearborn, Michigan headquarters on Monday.

Fiat Chrysler Automobiles NV's sales slid 10 percent, hampered by outsized drop-offs of two sedans it will soon stop making, and a rare decrease of 7 percent for its Jeep SUV brand. Cherokee sales were down 23 percent.

Ford, the second-biggest automaker in the U.S. market with a 15 percent share of sales through September, has not said when it will issue its sales report.

Analysts expect Ford to show a decline of between 9 percent and 11 percent from a year ago, which some analysts said was due to better discipline on the use of discounts. Others pointed out that the company stemmed production at North American F-150 pickup truck plants and sedan plants to counteract weak demand.

Comparisons to last October are pressured because of two fewer selling days. But even with that factored in, sales would likely have been weaker if not for the big consumer discounts, known as incentives, analysts said.

TrueCar Inc said October incentives industrywide rose nearly 16 percent from a year earlier, or about $3,600 per new vehicle sold.

Nissan Motor Co's sales fell 2.2 percent, though sales of its SUVs and pickup trucks rose 13 percent.