Sales at Orange County auto dealers rose 6.4% to 46,540 vehicles in the third quarter compared to the same period last year—the 16th consecutive quarterly improvement, according to the Newport Beach-based Orange County Automobile Dealers Association.

The figures are based on new retail car and light truck registrations in the county.

The local market is on pace for a 7.3% gain to 177,500 cars sold for the year.

Sales figures for the first nine months of 2014 show a 7.4% increase to 135,145 vehicles sold in OC.

National auto sales were up 6% compared to the same period last year.

Toyota Motor Corp. commanded the biggest share of the market in the county through September—18.7%— well above its 12.7% share in the nation. Honda Motor Co. followed with 12.8% of OC-based sales. Ford Motor Co. came in third, accounting for 8.2% of new auto sales.

Mazda Motor Corp., which has its North American operations in Irvine, garnered a 3.1% share of the market with 4,249 new registrations in the first nine months of this year, a 14.2% increase over the same period in 2013.

Fountain Valley-based Hyundai Motor America Inc.’s year-to-date market share was at 5.5%, with 7,456 vehicles sold here, a 6.7% decrease from a year earlier.

Kia Motors America Inc. in Irvine sold 5,687 vehicles through OC dealers in the first nine months of the year, good for a 5.5% year-over-year increase and a market share of 4.2%.

Mitsubishi Motors North America Inc.’s local sales dropped 3% to 840 vehicles and a market share of 0.6%. The Cypress-based brand’s national sales were up 29.8%.

Chrysler brands combined for a 5.1% share of the market with 6,871 vehicles sold in the county through September.

Of General Motors Co.’s brands--GMC, Buick, Cadillac and Chevrolet--the last one took the biggest share of the OC auto market—4.4%—with 5,892 new registrations, a 17.9% increase.

The report forecasts a 4.5% increase in auto sales to 185,500 vehicles for 2015.