Seeking to capture growing demand for fuel-efficient cars amid skyrocketing oil costs, General Motors (GM) is adding two shifts and about 2,500 hourly and salaried jobs at a Detroit assembly plant to ramp up production of sedans and electric cars.

The Detroit-Hamtramck plant will manufacture the new Chevrolet Malibu, a mid-size sedan, the next-generation Impala, a large sedan, as well as electric cars the Chevrolet Volt and Opel Ampera.

The automaker also said Wednesday it will invest $69 million in tooling and equipment to support the Impala. The move comes a month after GM announced a $121 million investment to support Malibu production.

“Filling this plant with new work is very satisfying because GM is dedicated to helping rebuild this city,” GM North America President Mark Reuss said at the plant Wednesday.

The jobs, which are adding to 1,121 hourly and salaried employees, will be filled by laid-off UAW members with possibility new hires to follow.

The additions are part of GM’s plan announced earlier this month to create or retain about 4,000 jobs and invest $2 billion in 17 manufacturing facilities in eight states. The company has previously added jobs in Bowling Green, Ky.; Toledo, Ohio; and Flint and Bay City, Mich.

GM said last week that after a four-week shutdown, the Detroit-Hamtramck plant will exclusively build Volt and Ampera electric cars with extended-range capability for the rest of the year.

Of the 16,000 electric vehicles being built at the plant this year, many will be exported to Canada, Europe and China. The production goal for 2012 is up to 60,000 with three-quarter of those to be sold in the U.S.

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