The reports said that the group of Rolls and Bentley car owners, mostly British and American millionaires, planned to offer more than 450 million pounds ($730 million) and have formed a new company called Crewe Motors, after the Rolls and Bentley factory, to launch their bid.

They have provided for about 350 million pounds in back-up capital for investment in future models, the reports said.

The terms would surpass the VW offer of 430 million pounds from Germany's Volkswagen AG, which itself beat a rival offer of 340 million pounds from BMW AG, it said.

The sale of Rolls-Royce Motor Cars by British engineering group Vickers Plc faces judgement day on Friday this week when shareholders look set to back the VW offer at an extraordinary general meeting in London.

He added that Vickers was confident of apositive vote and completion of the deal was seen by early July.

The reports said that the identity of Crewe Motors' backers remained a secret but they were described as business people and enthusiasts, including at least one multi-billionaire with an extensive collection of both luxury marques.