Bayerische Motoren Werke AG’s BMW brand topped Daimler AG’s Mercedes-Benz and other luxury auto makes in the U.S. last month, widening its lead for 2011 as the European automakers boosted discounts.

BMW’s U.S. deliveries, helped by sales of sport-utility vehicles and the new 5-Series sedan, rose 16 percent from a year earlier to 20,651, the Munich-based automaker said yesterday in a statement. Deliveries for the first five months of the year rose 13 percent to 92,068 vehicles, to lead Mercedes’ 90,274 sales and the 77,237 deliveries by Toyota Motor Corp’s Lexus, reported Bloomberg.

“BMW and Mercedes-Benz clearly will be on a photo finish for the rest of the year,” Jesse Toprak, vice president of industry trends at TrueCar.com in Santa Monica, California, said in a telephone interview. “Lexus, for the first time in many years, is clearly out of the running for the top spot.”

Mercedes’ discounts rose by 27 percent per vehicle in May and BMW increased its incentives by 6.7 percent, while discounts on Lexus models fell 51 percent, according to Truecar.

Lexus, based in Toyota City, Japan, has been the top- selling luxury auto brand in the U.S. on an annual basis for the past 11 years. Its lead over BMW narrowed to 9,216 last year, less than half the 19,473 gap in 2009. Mercedes finished in third place last year. Lexus sales last month tumbled 45 percent to 12,305, the company said in a statement.

“It would appear Lexus has suffered from a lack of supply,” Jim O’Donnell, head of BMW’s U.S. sales operations, said in an interview. “That’s unfortunate, but it’s one of those things.”

U.S. sales of BMW’s 5-Series models rose 84 percent last month when X3 SUV deliveries more than tripled to 2,350, the company said.

U.S. dealers sold 18,886 Mercedes-Benz cars and SUVs last month, 1.8 percent more than a year earlier, Stuttgart, Germany- based Daimler said in a statement.

The results exclude Daimler’s Sprinter vans and Smart cars and BMW’s Mini brand, which aren’t luxury vehicles.

General Motors Co.’s Cadillac luxury division’s sales fell 5.7 percent to 11,623 last month, as CTS sales rose 23 percent. Sales of the STS and DTS sedans, production of which ended this year, fell 68 percent and 34 percent, respectively.

Fleet sales fell 44 percent as GM tries to wean itself off such sales, said Kurt McNeil, Cadillac’s vice president of sales. Cadillac sold about 15 percent of its models to fleet buyers in May and aims to reduce that to about 10 percent by the end of the year, Todd Davis, a spokesman, said in an e-mail.

“A lot of that we drove with DTS and STS winding out of the portfolio,” McNeil said of the fleet-sales decline in a telephone interview yesterday. “The challenge is to just stay pure with our new products, which we are completely committed to doing.”

Nissan Motor Co.’s Infiniti sold 6,389 vehicles, a 21 percent decline from a year earlier, the company said in a statement.

Honda Motor Co., based in Tokyo, said in a statement that sales for its Acura brand fell 24 percent to 9,000 last month.

U.S. deliveries of Volkswagen AG’s Audi brand rose 14 percent to 10,457 vehicles, the company said in an e-mail.

Ford Motor Co. sold 7,399 Lincoln luxury vehicles in May, 4.6 percent fewer than a year earlier, according to a statement from the Dearborn, Michigan-based automaker.

Land Rover deliveries rose 6.7 percent to 2,891, while Jaguar sales gained 32 percent to 1,271, Mumbai-based Tata Motors Ltd. said in an e-mailed statement.