DETROIT -- General Motors will launch its next generation of full-sized Chevrolet trucks over about 15 months beginning early next year, dealer sources say.

A successful launch is critical to GM's turnaround. GM's full-sized trucks will be re-engineered and restyled for the 2007 model year. GM pushed the launch forward to get fresh versions of its most-profitable vehicles to market quickly.

Sales of the 2007 Tahoe SUV will begin in the first quarter of 2006. GM will follow with the Suburban and Avalanche SUVs and the Silverado 1500, 2500 and 3500 pickups.

Cadillac and GMC truck models that share components and chassis with the Chevrolet vehicles are expected to follow a similar schedule. The 2007 GMC Yukon and Cadillac Escalade SUVs are expected to debut about the same time as the Tahoe, for example.

Chevrolet's top dealers viewed the 2007 full-sized truck lines at a meeting late last month in Palm Springs, Calif. One dealer who attended said dealers saw the 2007 Chevrolet Tahoe, Suburban and Avalanche, "and pictures of the Silverado."

The Tahoe's styling is softer and is evolutionary rather than radically different, an industry source says. All sheet metal is new.

Dealers were told that the Chevrolet trucks would debut on the following timetable:

>>> Tahoe, first quarter 2006

>>> Suburban, second quarter 2006

>>> Avalanche, third quarter 2006

>>> Silverado 1500, fourth quarter 2006

>>> Silverado 2500, 3500, first quarter 2007

A dealer who asked not to be identified said the Tahoe is expected to arrive in February or March.