MUNICH, GERMANY - Bayerische Motoren Werke AG's 5 Series, the automaker's most profitable car, may be offered in hybrid, diesel and 4-cylinder versions to meet U.S. fuel-economy rules.

A hybrid may be available in the U.S. in 2011, Willem Rombauts, product manager for the 5 Series, said yesterday at a test-drive event in Philadelphia. Diesel and 4-cylinder models might reach BMW's second-largest market "in the next few years," he said.

Automakers are preparing to revamp their lineups to meet U.S. standards that target industry average fuel economy of 34.1 miles (54.9 kilometers) per gallon by 2016. BMW's cars and light trucks averaged 27.5 mpg and 23.1 mpg last year, according to the National Highway Traffic Safety Administration.

"There are different ways to lower fuel consumption, and we'll probably use most of them," Rombauts said in an interview. "You can bring hybrids, you can bring diesels. With us, it's going to be a broad range in every area."

The maker of BMW, Mini and Rolls-Royce vehicles doesn't offer a 4-cylinder engine in any model in the U.S., Rombauts said. A turbocharged 4-cylinder under development offers performance similar to that of the 6-cylinder engine in the new 528i, he said.

"Four cylinder will come to the U.S., and there's a good chance it will also come on the entry model of the 5 Series," Rombauts said, referring to the 528i.

Company executives on a March 18 conference call said BMW would have a 5 Series hybrid in 2011, without identifying the markets where it would be sold. They also said Munich-based BMW was developing 4-cylinder and diesel vehicles to be offered in the U.S., without specifying what models might have them.

BMW rose as much as 50 cents, or 1.3 percent, to 38.68 euros and traded at 38.67 euros as of 10:32 a.m. in Frankfurt. The shares have gained 21 percent this year, valuing the carmaker at 24.7 billion euros ($31.4 billion).

BMW said in January that it would sell its 7 Series large sedan with a 6-cylinder engine for the first time in 18 years. The company also said it would resume using 4-cylinder engines, without giving specifics. BMW's last four-cylinder U.S. car was in the 3 Series in 1999.

The 5 Series is BMW's most profitable car, according to Rich Brekus, the company's general manager for sales in North America. It generates fewer sales than the 3 Series, while selling for about $15,000 more.