General Motors Corp. is scrapping plans for a new plant in Flint, MI, to build gasoline engines for the upcoming Chevrolet Volt extended-range hybrid-electric vehicle.

The auto maker now says it will produce the 1.4L Family 0 engine at its existing Flint South plant.

GM in December put on hold construction of a new $370 million, 552,000-sq.-ft. (51,282-sq.-m) engine plant at a brownfield site adjacent to Flint South, due to its deteriorating financial position. It later revealed it initially would import engines from Austria for the Volt, which is slated to go into production in late 2010.

GM says the latest plan calls for installation of machinery and equipment to get under way this spring with production launch scheduled at the Flint South plant for December 2010. The facility will be equipped with about 150 “highly flexible” stations along the new assembly line that will allow production of multiple 4-cyl. engine families without the need to retool.

Investment at Flint South will total $250 million. GM isn’t saying what capacity will be on the new line, but says it will be the same as what was planned for the new facility, which was expected to create or retain 300 jobs at the Flint complex.

Flint South currently employs about 500 people, and GM says “some jobs” could be added once the new line comes in. The facility currently builds the 3.6L V-6 used in the Cadillac CTS and GM’s family of midsize cross/utility vehicles and the 3.7L inline 5-cyl. that goes into its midsize pickups and Hummer H3.

Floor space for the new line was freed up when output of the 4.2L inline 6-cyl. was discontinued. That engine was offered in GM’s now defunct midsize SUVs.