Bayerische Motoren Werke AG, the world’s biggest manufacturer of luxury vehicles, expanded its lead over Volkswagen AG’s Audi, buoyed by demand for the X3 sport-utility vehicle.

Sales at BMW’s namesake brand rose 9.3 percent to 128,446 vehicles in September as deliveries of the X3 more than tripled, the Munich-based automaker said today in a statement. Audi posted a 17 percent gain, delivering 120,200 autos on stronger demand in China, the Ingolstadt, Germany-based company said.

“It’s all holding up extremely well,” said Arndt Ellinghorst, an analyst with Credit Suisse in London. The growth rates of about 20 percent that BMW and Audi posted in China are “quite healthy.”

BMW, Audi, and Daimler AG’s Mercedes-Benz are targeting record sales this year and anticipate demand for high-end vehicles to outpace the broader auto market in the coming years, reported Bloomberg. European investor confidence fell to the lowest in more than two years this month on concern that the region’s debt crisis and weaker growth in emerging markets will hurt economic expansion.

“We made solid gains across the globe and once again achieved record sales for September,” Ian Robertson, BMW’s sales chief, said in the statement. The company is “on course” to meet its target of delivering 1.6 million vehicles this year and aims to maintain an “upward trend” in the fourth quarter, he said.

BMW rose as much as 3.7 percent to 52.78 euros and was up 3.6 percent at 4:16 p.m. in Frankfurt. The stock has fallen 10 percent this year, valuing the company at 33.8 billion euros. Daimler gained 3.8 percent to 35.28 euros and Volkswagen jumped 4.8 percent to 106.30 euros.

Audi aims to sell more than 300,000 vehicles in China for the first time after already surpassing last year’s total, Peter Schwarzenbauer, Audi’s sales chief, said in the statement. The carmaker also increased deliveries in debt-strapped countries such as Italy and Spain, helped by the A6 sedan and A1 subcompact, the company said.

“Growth is being driven above all by the emerging markets, primarily from China, but also from Brazil, Russia, India and Turkey,” said Marc-Rene Tonn, a Hamburg-based analyst with Warburg Research, who recommends buying Daimler and Volkswagen shares, and has a "hold" rating on BMW. “The question is how the sales values hold up there.”

BMW expanded its lead over Audi and Mercedes after the first nine months of 2011, delivering 1.02 million vehicles compared with Audi’s 973,200 and Mercedes’s 919,288. The Daimler unit, which aims to overtake Audi and BMW by 2020, remained in third place after sales last month edged up 2 percent to 120,982 cars and SUVs, the Stuttgart, Germany-based company said Oct. 5.

“It’s probably not going to get much better for Mercedes before 2013,” said Ellinghorst. Consumers are looking to trade down to smaller vehicles, a “weak” area for Mercedes, he said.

Mercedes’ best-selling C-Class will also face tougher competition next year, as BMW prepares to introduce a revamped version of the 3-Series sedan.