International Truck and Engine Corp. said it will indefinitely idle 315 employees at an Indianapolis engine plant Sept. 27 because the truckmaker expects lower sales and a need for fewer workers on a new production line, Bloomberg News reported. The employees will be laid off a month from now as the factory prepares to produce a new diesel engine for Ford Motor Co.'s Super Duty light trucks that requires fewer assembly workers. The 6.0-liter Power Stroke engine soon will be produced at the plant, while an older 7.3-liter model will be phased out due to lower demand among customers and new weight, fuel economy, emissions and noise requirements from Ford. Earlier this month, International truck group president Steve Keate said that a slide in Class 8 truck sales could lead to eventual layoffs at its Chatham, Ontario, plant. Keate said about 400 of the plant's 1,000 workers could be affected.