June 8 (Bloomberg) -- General Motors Corp.'s Saturn, the fastest-growing brand in the U.S. this year, may add a smaller car because of rising demand for fuel-efficient models.

``We think there is definitely room at the bottom for an economy car for Saturn,'' Lisa Hutchinson, the brand's product- development director, said today in an interview in New York. ``There is a growing interest in fuel economy as prices have gone up.''

She didn't say when the division might add the car, known as a subcompact. The Opel Corsa subcompact, one of GM's most popular models in Europe, is a possible candidate for Saturn's lineup, she said. Saturn and Opel have been sharing vehicles.

Saturn already has benefited from new models such as the Aura sedan and Outlook sport-utility vehicle that have helped boost its U.S. sales 30 percent through May. Subcompact sales have increased 43 percent, the most of any vehicle segment, as average gasoline prices rose as high as a record $3.23 a gallon.

Subcompacts include models such as Toyota Motor Corp.'s Yaris, GM's Chevrolet Aveo and Honda Motor Co.'s Fit.

``Those are a good vehicle to have in your lineup because they generate interest in the brand and showroom traffic,'' said Jim Hossack, an analyst at AutoPacific Inc. in Tustin, California. ``It's a reasonably good fit for Saturn, a good idea.''

Saturn's smallest vehicle now is the Ion car, which the division will replace late this year with the Opel Astra.

The current lineup for Saturn includes the Aura, added in last year's second half; the Ion; the Sky sports car, added in 2006's first half; the Outlook, added late last year; the Relay minivan; and the Vue SUV. The division also began selling a gasoline-electric hybrid version of the Vue in late 2006.

The division will have five 2008 models, Hutchinson said.

Competitive Test Drives

Saturn dealerships on June 11 will begin a program that lets their prospective buyers test-drive Toyota Camry and Honda Accord sedans for comparison to the Aura.

All but about five of Saturn's 430 U.S. dealerships volunteered for the program, which runs through July 31, Hutchinson said. The dealers will buy the Toyota and Honda vehicles themselves, she said. Hutchinson declined to say how much the program will cost.

The Camry is the best-selling car in the U.S. this year. The Accord is third, behind the Camry and Toyota's Corolla. Sales through May totaled 193,900 for the Camry, 153,431 for the Accord and 22,535 for the Aura.

GM shares rose $1.32, or 4.4 percent, to $31 at 4:20 p.m. in New York Stock Exchange composite trading. They have gained less than 1 percent this year.

To contact the reporter on this story: Greg Bensinger in New York at gbensinger1@bloomberg.net

Last Updated: June 8, 2007 17:27 EDT