DETROIT  The brand that was once hailed as an important part of the future of General Motors now will be part of its past.

G.M. said Tuesday that it would phase out its Saturn brand by 2012. It does not plan to develop any more new vehicles for Saturn, which began 19 years ago as an effort to attract owners of small Japanese cars.

G.M. also said it was considering its options for the Pontiac division. The Pontiac name, part of the car business since 1932, could remain on some models, but may no longer be a separate division. G.M. said Pontiac would be a “focused brand” with fewer models.

The disclosures by G.M., contained in a viability plan submitted to the government, means that G.M. plans to cut its brands in half, to four: Chevrolet, Cadillac, Buick and GMC.