General Motors expects production at seven assembly sites affected by parts shortages caused by a fire at a major supplier’s plant to resume by Tuesday.

However, a Mazda plant in Flat Rock, MI, also receiving parts from Magna International’s burned-out Howell, MI, facility will stay down for the week.

Mazda suspended production of the Mazda6 sedan at the AutoAlliance plant, which also builds the Ford Mustang, due to a shortage of Magna-made headliners and a handful of other parts.

Meantime, Ford says it is suspending Mustang production due to a parts shortage at AAI, a joint venture between the two auto makers.

Ford spokeswoman Marcey Evans says the Mustang shutdown is not a result of the Magna fire, but declines to reveal any further information, citing Ford policy.

GM’s Lordstown, OH, assembly plant, which builds the new-for-’11 Chevy Cruze compact car, gets back on its 3-shift schedule tomorrow after a 4-day hiatus because of the blaze.

The two shifts at GM’s Flint, MI, heavy-duty pickup plant went back to work Monday, and the auto maker’s Delta Twp. facility gets its third shift back tomorrow.

Delta Twp. outside Lansing, builds the Chevy Traverse, GMC Acadia and Buick Enclave large cross/utility vehicles. The nearby Lansing Grand River assembly plant, responsible for building the Cadillac CTS lineup, also has resumed regular production.

GM’s Fort Wayne, IN, assembly plant, which builds light-duty pickups, also has returned to its normal schedule. Facilities in Arlington, TX; Oshawa, ON, Canada; and Detroit-Hamtramck also are back on schedule.

GM spokesman Chris Lee says despite resuming a regular schedule, affected plants could still face shortened shifts or changes to model mix. A plan aimed at regaining lost units is being formulated, he says.

Magna spokeswoman Tracy Fuerst tells Ward’s roughly 50% of the Howell facility’s operations are up and running today and supplies to customers have restarted on a limited basis.

Nearly the entire workforce at the plant has been called back to assist with recovery efforts and normal operations, but Fuerst says in an e-mail the supplier cannot provide a timetable for when it might become fully operational.

Chrysler, also customer of the Magna plant, reports no parts problems from the fire.

– with Byron Pope