British-based super-luxury BMW subsidiary Rolls-Royce Motor Cars is to produce an additional model line to slot below the Phantom range, RR's chairman and CEO Ian Robertson said at the Paris motor show.

The car will launch "'before the end of the decade", and priced in the range of "EUR200-300,000 before taxes", said Robertson.

It will be built at Rolls-Royce's new plant at Goodwood in southern England. The Phantom is already built there using an aluminium body shell brought in from BMW's Dingolfing plant in Germany, and a BMW-made V12 engine.

The Goodwood plant will not be extended, Robertson said. Currently it works just one shift; this will be increased to cover the new model range.

The new car's body shell will also be brought in from abroad. Questioned on whether it would be based on a BMW steel monocoque or whether it would have a bespoke shell like the Phantom, Robertson would not comment, nor would he say whether it would be steel or aluminium, or whether it would have the Phantom's rear-hinged coach door system.

However, he said the new car would be an "authentic Rolls-Royce" and would have "a unique powertrain". This would be petrol fuelled, he said, with no diesel option, and it would be derived from a BMW unit.

A team led by R-R design chief Ian Cameron has produced several design proposals, from which a final selection will soon be made, said Robertson.

He would not predict production numbers, beyond saying that Rolls-Royce total output would not go much beyond "a couple of thousand" in total in the medium term.

Robertson also came close to confirming the Phantom-based coupe, previewed as the EX101 concept. He said a final decision over production has yet to be made, "But I will try not to disappoint the many customers" who have asked for it.

Robertson said the number of Phantoms built in 2006 will be approximately the same as 2005's 796. Early in 2007 a convertible version will be launched, for which RR already has "several hundred" orders.

Paul Horrell