Troubled German carmaker Opel said Tuesday board member Thomas Sedran will take over as interim chief until a permanent successor can be found for Karl-Friedrich Stracke, who quit last week. Opel said in a statement its supervisory board appointed 47-year-old Sedran as interim head of the loss-making subsidiary of US auto giant General Motors \"with immediate effect.\" Sedran is already the board member responsible for operations and business strategy, a position he has held since April 1. \"He will assume the seat of chief executive ... until a successor can be announced\" for Stracke, 56, who stepped down as Opel\'s chief and head of General Motors Europe last week, the statement said. In June, Opel\'s supervisory board approved a deep restructuring plan to steer the firm back into profit. GM\'s European operations have run up billions of dollars in losses over the past 10 years and it had planned to sell Opel at one stage but pulled back when it could not find a suitable buyer. \"We\'re pressing ahead with the implementation and optimisiation of our business plan,\" said Opel supervisory board chief and GM Europe president Steve Girsky. \"We will cut down bureaucracy and change our company\'s corporate culture,\" he said. Sedran is Opel\'s fourth new chief within a period of just three years and the constant game of musical chairs at the head of the brand is doing little to help its reputation. Opel\'s market share in Europe is falling, at just 6.9 percent in June compared with 7.6 percent a year earlier, as sales plunge 12.2 percent. According to German media reports, Opel is seeking to recruit someone from outside the company to fill the driving seat, with names such as former Porsche chief Wendelin Wiedeking mooted as possible candidates. Herbert Demel, a former executive at Canadian car parts supplier Magna, ex-Daimler manager Rainer Schmueckle and Karl-Thomas Neumann of Volkswagen have also been seen as potential candidates. Sedran, born in Augsburg in southern Germany, formerly worked as a corporate consultant with firms such as AlixPartners and Roland Berger. At AlixPartners he was division head for the auto industry and has worked closely with Opel in that function since 2009.