(Reuters) - General Motors Co (GM.N) said it will invest about $332 million in four manufacturing sites to produce more fuel-efficient engines and transmission systems.
So far this year, the carmaker has announced $1.2 billion in investments in its North American plants. GM has said it would invest $1.5 billion in those plants this year.
The investments will boost production of a new Ecotec small gas engine, a new V6 engine, eight-speed transmission and tooling for an existing six-speed transmission.
The carmarker is also raising its powertrain investment in two Michigan plants by $46 million to support production of the new V6 engine.
Shares of the Detroit-based company closed at $27.80 on Wednesday on the New York Stock Exchange.
(Reporting by Jochelle Mendonca in Bangalore; Editing by Joyjeet Das)