Citic Resources Holdings boosted its stake in Australian miner Macarthur Coal to more than 20%, the South China Morning Post reported. Citic Resources lifted its holding to 20.39% from 17.66% for what Goldman Sachs estimates is US$96 million, and in doing so overtook ArcelorMittal as Macarthur’s biggest shareholder. The paper said a possible bidding war between Macarthur’s major shareholders – Citic Resources, ArcelorMittal and South Korean steelmaker Posco – is now possible. But an investment banker who spoke to the newspaper said it would be difficult for either of the three shareholders to launch a general offer for Macarthur without the agreement of the other two. Until recently there had been rumors that Citic Resources intended to exit its investment in Macarthur.