A fourth bidder has shown an interest in acquiring General Motors' European Opel and Vauxhall brands.

Bloomberg News, citing 'people familiar with the matter', said an unnamed Chinese company made its intentions known yesterday, 24 hours after the German government's deadline.

The sources added, however, that a specific offer may not materialise. GM is selling its European operations as it prepares for a probable 1 June bankruptcy. Fiat, Canadian supplier Magna International and RHJ International, a buyout firm that has automotive assets, including some former holdings of private equity firm Ripplewood Holdings, have already submitted their bids.

The bids from Magna and RHJ include a cash component, while Fiat's offer requires EUR7bn (US$9.7 bn) of financing to reorganise Opel/Vauxhall's operations. Sources said Fiat's bid has two parts: an offer for the Opel and Vauxhall units plus an alternative plan to also buy GM's operations in Brazil and Argentina.

The Italian carmaker's chief executive Sergio Marchionne has said he wants to create a new company that combines Fiat's auto unit with Chrysler, GM Europe and possibly GM Latin America. Magna wants to take a 20% stake in Opel, apparently with additional equity acquired by its two bid partners, Russian vehicle manufacturer OAO GAZ and state-run OAO Sberbank.

The German government secured EUR1.5bn in bridg­ing finance for Opel until a deal is completed. Parent company General Motors said the process could take months while the suitors conduct due diligence.