Germany’s Economy Minister says he so far remains unpersuaded by any of the bids to buy Opel.Karl Theodor zu Guttenberg is leading efforts to find a viable lifeline for the General Motors sister company. He has confirmed Fiat’s renewed offer from yesterday is being looked into. Rival bidders, Austrian/Canadian car parts giant Magna and investment firm RHJ International, have yet to respond to Fiat Chief Executive Sergio Marchionne’s latest bid. Union leaders at Opel fear any takeover will lead to thousands of job cuts. In the case of Fiat Wolfgang Meinig a car industry expert agrees. He said: ‘‘Fiat is one of the European firms which are in debt, and aren’t able to get hold of liquid assets like many of the German manufacturers. They have billions in shortfalls, so from that point of view, Fiat can’t spend money on Chrysler or Opel.’‘ Fiat’s improved bid came after a number of German politicians threw their weight behind Magna, which is in partnership with Sberbank and has close links with Russian prime minister Vladimir Putin. Manga’s boss Siegfried Wolf has pledged none of Opel’s German plants will close if its offer is successful.