General Motors will remain committed to Saab, but thinks it must double output to make money consistently, GM Vice Chairman Robert Lutz has said in a newspaper interview.

"We like the brand and we want to retain it," says Lutz, confirming his company's determination to persevere with Saab after 16 years of involvement.

But there will be changes, he said. "You cannot make a business case under 200,000 to 250,000 annual volume - that is almost impossible," says Lutz.

Since GM bought half of Saab's automotive division back in 1989, production has not reached those figures. Its record year was 2000 - when GM took over full ownership - when 133,013 units were sold. Last year Saab built 128,000 cars.

Saab lost $200 million (£105m) in 2004 because of poor global sales, adverse currency levels and high manufacturing costs at its Trollhattan plant.

Possible scenarios for increasing profit levels involves sharing platforms, engines and transmissions with other brands (as will be the case with a forthcoming Cadillac, based on the 9-3 platform); building the next-generation 9-3 at the Opel factory in Rüsselsheim; continuing other Saab production at Trollattan in Sweden but also building non-Saab-branded vehicles there; and facelifting the 9-5 while GM considers whether to replace it.