DETROIT -- General Motors' efforts to revitalize Saturn will pay off handsomely for the brand this year, a GM senior executive says.

While GM's Chevrolet brand will still see the most growth in terms of unit sales, Saturn will experience the greatest "rapid overall percentage expansion" of GM's eight brands this year, Robert Lutz, GM's vice chairman for global product development, said in an interview with Automotive News.

Lutz credited the expansion to the new Saturn lineup. Saturn dealers already are sold out of the new Sky roadster into next year, Lutz said. Dealers will get the Aura sedan, Outlook crossover, Vue Green line hybrid crossover and a Sky Red line high-performance roadster this year. Saturn will get a rebadged Opel Astra sedan next year to replace the Ion.

"When you think of where Saturn was two years ago, compared to where they will be 18 months from now, it'll be unrecognizably different," Lutz said.

Lutz stopped short of predicting how much of a percentage sales increase Saturn might experience this year. Saturn sold 64,324 light vehicles in the United States through April. That's up 1.2 percent from 63,581 in the year-ago period.

Lutz said GM is studying increasing production of the Sky and the Pontiac Solstice roadster, which are built on the same rear-wheel-drive platform in Wilmington, Del. GM had aimed to build 20,000 Solstices and 10,000 Skys this year, but Lutz said the plant has the capacity to build more.

Globally, Lutz said, Chevrolet is on "an extremely fast growth curve." The brand sold more than 4 million vehicles worldwide last year, he said. In the United States last year, Chevrolet sold 2,651,124 cars and light trucks.