General Motors Corp. has selected three additional suppliers as part of its strategy to hand off a major portion of the development of future GM vehicles.

Lear Corp., Magna International Inc.’s Intier Automotive and Detroit-based Venture Industries Inc. each will be assigned a specific GM platform and will be responsible for developing interiors for next-generation vehicles from the platform, Bo Andersson, executive in charge of worldwide purchasing at GM, tells Ward’s.

Mr. Andersson made his remarks Friday after his speech at the automotive Management Briefing Seminars in Traverse City, MI.

Lear, Intier and Venture join Johnson Controls Inc. as lead interior integrators. GM selected JCI in May to develop interiors for next-generation minivans.

Like with JCI, the three others will take on some GM engineers as part of the interior outsourcing strategy. “I’m very cautious as we move forward because this is a big thing,” Mr. Andersson says.

Union officials are lukewarm on the concept because of the concern that JCI, if given the authority, would select non-union Tier 2 and 3 suppliers. For now, GM will remain responsible for selecting all suppliers, Mr. Andersson says. But as the strategy moves forward, the lead systems integrators may gain clout in influencing those sourcing decisions.