American automotive giant General Motors says it will continue to adopt a dual approach to using pgms in its emission controls systems.

The firm says that it will continue to alternate between palladium and platinum in the technology as it minimises the dependency on one metal, helping the firm to negotiate difficult price increases in the respective metals.

At present the firm is moving back towards palladium, as GM spokesman Thomas Hill explained.

"Now prices have swung the other way - GM again has rapidly re-engineered and certified a lot of our systems to substitute palladium back for the platinum," he told OsterDowjones.

"GM has a very effective systems engineering process that focuses on the entire emissions control system which includes engine calibrations and controls hardware and the catalytic converter performance - best system cost and performance is the objective," he added.

He went on to stress the flexible nature of the company's approach, saying he thought it unlikely GM would "lock into one technical approach on emissions after treatment".

In that vein GM has managed to structure its platinum group metals usage, and is said to be "on track" to meet its target of reducing platinum group metals usage by 17 per cent by 2006.