DETROIT -- Magna International Inc. will build the convertible top for the Chevrolet Camaro.

General Motors Co. reassigned the contract to Magna, of Aurora, Ontario, last year when a rival supplier, Germany's Edscha AG, filed for insolvency, said two sources familiar with the discussions.

GM put first-year Camaro convertible production at about 20,000 units, the sources say, which could make it one of the largest North American ragtop contracts. Only the Ford Mustang, with production of about 20,000 convertibles last year, would rival that volume.

GM spokesman Adam Denison declined to comment.

North American convertible system production is at its lowest point in years. Only 41,380 were built through late November of last year, down from 200,000 four years ago, say industry sources.

The drastic reduction has hit convertible-top builders including Edscha, which initially had won the Camaro program. Webasto AG, a leading car top supplier, acquired Edscha's assets last year.

GM worried that Edscha's troubles would spill over into its Camaro program, the sources say.

Drastic sales declines last year and GM's bankruptcy forced the automaker to kill several convertible programs, including the Pontiac Solstice, Saturn Sky and Cadillac XLR roadster.

Those programs were supplied by Magna's Car Top Systems group which also supplies the Corvette convertible.

Magna is slated to build the Camaro top at its Bowling Green, Ky., plant, with fabric from its Mexican operations.

A spokesman for Magna, North America's largest parts maker, declined to comment.

Last May, GM spokesman Terry Rhadigan told Automotive News that the Camaro convertible would be ready for production in the first quarter of 2011. But that date appears to have slipped to the second half of 2011, sources said.