A total of 400 jobs are being axed at the Wiltshire-based car-pressing subsidiary of BMW.
Swindon Pressings is blaming the cuts on a decline in contracts from other car-makers like MG Rover and Landrover.
The trade union representative at BMW,
Jim D'Avila, said the jobs will go between now and next summer.
"We hoped the company would attract more work to Swindon, minimising or even eliminating the need for further cutbacks in the workforce," he said.
The last round of redundancies was in January, when 330 job losses were announced.
But in June, the company said it was to invest �40m in the Swindon plant to supply the main bodywork for the new Mini convertible car.