Europe's auto market has grown for 14 straight months after a six-year slump but remains well short of its peak before the financial crisis.
Still, the 6.5 percent gain in the 28-nation EU was the second-highest percentage increase in a month of October in that region in the past eight years, the data showed.
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Germany, Europe's biggest single market and home of VW, BMW and Daimler was up 3.7 percent to 275,320 while second-placed UK jumped 14.2 percent to 179,714.
By contrast, No. 3 market France slipped 3.8 percent, a reflection of near-stagnant growth in the euro zone's second-biggest economy.
Year-to-date deliveries in the EU plus EFTA region rose 5.9 percent to 11.02 million vehicles from 10.41 million in the year-earlier period, ACEA data showed.
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VW, Europe's biggest automaker, and PSA Peugeot Citroen rose 6.9 percent and 1.1 percent respectively while luxury nameplates BMW and Daimler were up 9.4 percent and 2.2 percent.
The only major group to post lower sales in October was General Motors, grappling with a 5.1 percent drop as the withdrawal of the Chevrolet brand from Europe outweighed a 12 percent gain by the Opel nameplate.