(November 22, 2011) SPRING HILL, Tenn. — General Motors will invest $61 million to bring its idled Spring Hill assembly plant back to life as one of the world’s most-flexible manufacturing facilities capable of building any GM car or crossover based on customer demand or manufacturing need.

The investment will create 594 hourly jobs and 91 salaried positions for the flexible operation scheduled to begin with the hot-selling Chevrolet Equinox in the second half of 2012.

The additional production will supplement Equinox production in Canada, the main assembly sites of the midsize crossover vehicle and its sibling the GMC Terrain.

The Equinox has been popular — U.S. sales were up 18 percent in October — that GM has increased production three times since it went into production in 2009.

GM also announced Monday a second investment of $183 million for future midsize vehicles to be built at Spring Hill, located about 40 miles south of Nashville. Timing was not announced, but that investment is expected to create an additional 1,090 hourly and 106 salaried positions.

“Spring Hill has a history as one of GM’s most innovative and flexible plants,” said Cathy Clegg, vice president of GM Labor Relations. “We’re pleased that, working together with the UAW, we were able to build on that history and develop a plan to resume production at Spring Hill.”

The potential for Spring Hill’s future role was discussed as a part of negotiations for a four-year national labor agreement ratified in October.

Equinox production is only the start for Spring Hill Flex. Operators will be capable of building a variety of products on a range of platforms — covering for plants being retooled for new products and also allowing real-time reaction to sales spikes in a given car or crossover.

Spring Hill powertrain and stamping operations, part of the integrated complex that was the home to the former Saturn brand from 1990 to 2007 and the Chevrolet Traverse large crossover into 2009, are still operating. In fact, GM has invested $515 million in the engine operations in the last 14 months for current and next-generation Ecotec 4-cylinder engine production.