Holding company RHJ International has emerged this week as a strong challenger to Magna International in the bidding war for General Motors' Opel division. The Belgium-based industrial holding firm, which is linked to the U.S. buyout company Ripplewood, confirmed that it was in advanced talks to buy a majority stake in Opel and hopes to reach an agreement with GM by the end of this week.

Automotive parts supplier Magna International had long been seen as the front-runner for Opel and had aimed to sign a deal with GM by July 15, but with talks between the two companies suffering a hold up, newcomers like RHJ and China's Beijing Automotive Industry Corporation (BAIC) are also vying for a piece of the Opel pie.

RHJ waited until this week to confirm its interest in Opel because only now did it feel it was close enough to its goal to go public, spokesman Arnaud Denis explained to Automotive News.

While Magna was seeking roughly $6.5 billion from the German government to secure the deal with Opel, RHJ only needs $5.3 billion, potentially making it the better suitor for Opel.

Other groups still in the bidding for Opel include Fiat and Magna’s consortium partner Sherbank.