DETROIT (Reuters) - Automakers reported their strongest U.S. October sales in a decade on Monday on strong demand for brawny pickup trucks and roomy SUVs, but top-seller General Motors Co (>> General Motors Company) missed expectations.

The results, often an early snapshot of U.S. consumer spending, continued the strong run for a sector that has outraced the broader economy since 2010.

“The U.S. economy has steadily improved all year and now we are poised for a stronger expansion backed by an improved job market, higher consumer confidence and lower fuel prices,” said Kurt McNeil, GM's U.S. sales chief.

U.S. October auto sales increased 6.1 percent to 1.28 million vehicles, slightly higher than analysts' expectations, according to Autodata Corp.

On a seasonally adjusted annualised basis, sales for the month were 16.46 million vehicles, which was near the 16.49 million vehicles forecast by a Thomson Reuters poll of economists.

The last time October sales were this high was in 2004 when the rate was 17.1 million vehicles on an annualised basis, according to Autodata and government statistics.

Topping analysts' consensus were Ford Motor Co (>> Ford Motor Company), Chrysler Group and Nissan Motor Co Ltd (>> Nissan Motor Co Ltd).

In addition to GM, Honda Motor Co Ltd (>> Honda Motor Co Ltd) also missed estimates, while Toyota Motor Corp (>> Toyota Motor Corp) met expectations.

Declining gasoline prices helped boost demand for SUVs and crossovers. Ford said utility vehicles and trucks accounted for 72 percent of its sales, up from 68.5 percent a year ago.

Fred Diaz, U.S. chief for the Nissan brand, said a confluence of factors including pent-up demand, lower gasoline prices and improving consumer confidence will mean strong sales through December. Consumer sentiment is at its highest level since 2007.

Chrysler Group's U.S. October sales rose 22 percent to 170,480 vehicles on strong pickup truck and Jeep SUV demand. Chrysler is a unit of Fiat Chrysler Automobiles  (>> FIAT SPA).

Ford sales fell 2 percent to 188,654 vehicles, but the decline was expected because it has lowered production of the F-150 pickup in recent months during the transition to a redesigned aluminum-bodied model that goes on sale later this year.

GM sales inched up 0.2 percent to 226,819 vehicles, and the company said it is taking steps to boost profit at the cost of total sales by lowering fleet sales of large SUVs. Analysts also pointed to GM's record-high average selling prices for its vehicles.

GM is well-laden with truck inventory, which bodes well in the lucrative pickup truck market in the last quarter, when truck sales traditionally rise, said John Krafcik, president of TrueCar.

Toyota sales rose 7 percent to 180,580 vehicles.

Nissan and Honda each reported robust sales of crossover models and record October U.S. sales for their core brands.

Chrysler's Ram pickup truck sales rose 33 percent. Sales of GM's pickup trucks, including the Chevrolet Silverado and the GMC Sierra, gained 16 percent, to 68,530.

Ford's F-Series sales slipped 0.6 percent in October to 63,410. It was a rare beat by GM's pickup trucks over Ford's F-Series.

(Editing by Lisa Von Ahn, Jeffrey Benkoe and Matthew Lewis)

By Bernie Woodall and Ben Klayman