Bayerische Motoren Werke AG, the world’s largest maker of luxury vehicles, earned record per-car profit in the second quarter as demand for the 5-Series sedan helped it beat Volkswagen AG’s Audi.

BMW generated the highest profit margin of the top three luxury-car makers, with its auto unit posting earnings before interest and taxes equivalent to 14.4 percent of sales, up from 9.6 percent a year earlier. That beat margins of 11.8 percent at Audi and 10.7 percent at Daimler AG’s Mercedes-Benz, according to Bloomberg.

“For an analyst who’s covered BMW for 11 years it’s amazing to see this level of earnings,” said Max Warburton, a London-based Sanford C. Bernstein analyst with an “outperform” rating on the stock. “At no point in the past would it have been imaginable that this company could make margins of this level.”

Demand for the revamped 5-Series sedan and X3 sport-utility vehicle helped the maker of BMW, Mini, and Rolls-Royce models keep its high-end segment lead. Deliveries this year of the $45,050 5-Series have jumped 80 percent and the $36,750 X3 has more than doubled, fueling an 18 percent rise in the BMW brand’s first-half deliveries. Audi, which passed Mercedes this year and aims to topple BMW by 2015, also boosted sales 18 percent.

BMW closed down 1.92 euros, or 2.8 percent, at 65.79 euros, after gaining as much as 2.4 percent in Frankfurt trading earlier in the day. The stock has risen 12 percent this year, valuing the company at 42 billion euros ($60 billion). VW is up 9 percent in 2011, while Daimler has dropped 6.5 percent.

BMW’s second-quarter Ebit climbed 66 percent to 2.86 billion euros, the Munich-based carmaker said today. Profit beat the 2.3 billion-euro average estimate of 17 analysts surveyed by Bloomberg.

“This is not a one-time event for BMW,” said Arndt Ellinghorst, a London-based Credit Suisse analyst with an “outperform” rating on the shares. “They have the strongest product lineup and best execution in the market.”

Germany’s luxury-car makers are ramping up production to satisfy growing demand in China and rebounding spending in the U.S. Mercedes is building a factory in Hungary and expanding a plant in Alabama, while Audi has added production in Spain.

BMW will expand a South Carolina factory to 300,000 vehicles next year from 270,000 in 2011, and will likely decide in favor of building a new facility to assemble vehicles in Brazil from parts produced at other plants, Chief Executive Officer Norbert Reithofer said today.

“We are producing at the limit” and the waits for some models like the X3 are “too long,” said Reithofer.

Second-quarter net income more than doubled to 1.81 billion euros from 834 million euros as revenue gained 17 percent to 17.9 billion euros. Earnings were boosted by 464 million euros in one-time gains from releasing risk provisions. Excluding the one-time gains, BMW generated an auto margin of 13.9 percent.

BMW raised its 2011 profit and sales forecasts on July 12, citing strong demand for its vehicles. The company today said that ebit at its auto division will exceed 10 percent of revenue in 2011, excluding one-time effects. Sales are projected to rise to more than 1.6 million vehicles.

“From today’s perspective, it seems unlikely that we will be able to maintain the high ebit margin of the second quarter through the rest of the year,” Chief Financial Officer Friedrich Eichiner said.

The increase in deliveries declined to about 7 percent in July and growth will likely be slower overall in the second half because of lineup changes and higher deliveries a year earlier, the carmaker said.

“Global risks continue to increase rather than decrease,” said Reithofer. “Concerted action of the international community is required to be able to maintain economic and financial strength worldwide.”

BMW will introduce an overhauled version of the 1-Series compact in September in a bid to outsell Audi’s A3. Model introductions will add about 500 million euros to expenses in the final six months of 2011, while higher raw material prices will increase costs by more than 100 million euros, Eichiner said. The company is targeting margins in a range of 8 percent to 10 percent on average after this year.

“BMW’s margins have peaked,” said Juergen Pieper, a Frankfurt-based analyst with Bankhaus Metzler who has a “sell” rating on the stock. “The best phase of the cycle is behind it, as the product mix will start deteriorating with the 1-Series.”