GM plans new investment in New York plant

General Motors Corp. said Thursday it was planning to invest in its engine plant in Tonawanda, New York, but the automaker declined to give further details.

An announcement is expected Friday.

Union representatives and state and local officials have been trying to secure production of GM's 4.5-liter diesel engine for some pickup trucks and sport utility vehicles for the 2010 model year.

Senator Hillary Rodham Clinton has written to GM Chief Executive Rick Wagoner supporting efforts for production of the engine at the upstate New York plant.

In May, Erie County officials approved a $350,000 sales tax break to clinch the GM investment in the plant.

In January, GM (Charts, Fortune 500) said it would invest $300 million in the plant to make new V-8 engines for its luxury vehicles, slated for production in 2009. That announcement brought GM's total investment in the plant to $1.5 billion over the last decade.

The plant employs 1,860 people and currently makes engines for several GM vehicles, including the Chevrolet Cobalt, HHR, Malibu and Impala and the Saturn Ion.