According to Reuters, Deutsche Bank on Tuesday said it had downgraded US carmakers General Motors and Ford to "sell" from "hold" on concerns of a prolonged decline for US vehicle demand.

The bank also said it had downgraded automotive parts suppliers Delphi and Visteon to "sell" from "hold", Reuters added.

"Over the next few years, fewer vehicles will be reaching the 'peak scrappage age', and fewer vehicles will be coming off lease. Our analysis suggests that these structural factors could put significant downward pressure on auto demand through 2005," Reuters cited Deutsche Bank analyst Rod Lache as saying.

According to Reuters, the bank cut its target price on GM to $US24 from $32 and on Ford to $5.0 from $7.5. Its target for Delphi was revised to $6.00 from $8.00 and its target for Visteon cut to $4.00 from $8.00.

"Price deflation could get worse, as North American capacity utilisation rates decline...and the market share declines for the 'Big Three' could accelerate," Lache said, according to Reuters.