MORAINE, Ohio – General Motors Corp. said Friday it will shut down its SUV assembly plant here on Dec. 23 as the company shifts focus to smaller vehicles.

GM spokesman Chris Lee said employees gathered in the plant Friday afternoon were informed of the closing date. Some 1,100 remaining workers are affected.

The automaker earlier this year announced plans to close the plant by the summer of 2010 or sooner, then accelerated shutdown plans as part of companywide cost-cutting moves.

Union leaders have said they were expecting the plant in this southern suburb of Dayton to shut down by January or February. Messages seeking comment were left for the International Union of Electronic Workers-Communication Workers of America.

GM recently reduced operations at the factory to a single shift, eliminating 400 to 500 jobs.

The company had earlier planned a production break in December, but Lee said Friday the plant will keep up operations until the closing date to make sure all remaining customer orders are filled.

A customer move away from sport utility vehicles to smaller vehicles amid high gas prices had led to the shutdown plans.

The factory assembles the GMC Envoy, Chevrolet Trailblazer and Saab 9-7X.

General Motors turned down a $56 million tax credit and grant package from the Ohio Department of Development to keep the plant open.