IC Corp.'s parent company, Warrenville, Ill.-based Navistar, told employees Thursday it would cease bus production operations at its Conway plant.

"We have to consolidate our bus-assembly operations into one facility," Navistar spokesman Roy Wiley said. "Unfortunately for Conway, Tulsa is a much newer facility."

He said the economy has reduced orders from school districts. Wiley said a smaller operation would continue at the plant, making parts for buses.

The plant also laid off 170 workers in March.

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