The race to take over General Motors Corp.'s Opel unit was reduced to a duel yesterday after GM jettisoned an offer from China's Beijing Automotive Industry Corp. (BAIC), leaving just Magna International Inc. and RHJ International standing. "We have agreed to continue detailed talks with both Magna and RHJI," said John Smith, GM's chief negotiator for the sale of Adam Opel GmbH, the auto maker's European unit. Magna enjoys the support of the German government and the powerful unions. The battle is far from won, though, as GM is thought to be leaning toward RHJ. MG.A (TSX) rose 81 cents to $53.22. RHJI (Brussels) rose 3 euro cents to €4.45 ($6.85)