General Motors on Thursday will announce plans to invest $US300 million in a Michigan plant to make a six-speed transmission for rear-wheel drive cars, officials familiar with the plans told Reuters on Wednesday.

GM’s investment at its Willow Run Transmission plant in Ypsilanti will save hundreds of the plant’s 4,000 hourly jobs, the sources told Reuters.

Reuters noted that, in November, the state of Michigan said GM would receive a $17.1 million state single-business tax credit in return for a $300 million investment at Willow Run.

The company and the union were still holding talks on Wednesday to determine the amount of component work to be done inside the plant, rather than out-sourced, which would affect the amount of investment, union sources told Reuters.

According to Reuters, the sources said that production of the new six-speed transmissions would begin in 2005.

Reuters said that, last October, GM and Ford agreed to jointly-develop a six-speed transmission for front-wheel drive cars. That transmission is not expected to go into production until the latter half of this decade, and Willow Run is among several GM plants competing for that work, the sources told Reuters.