Anglo American, the UK-listed multi-metal mining giant allegedly eyeing up a counter bid for Macarthur Coal, has walked away from the potential acquisition, according to people close to the situation.Australian miner Marcarthur had recently backed an improved bid from Peabody Energy Corp and ArcelorMittal, which valued the firm at A$4.83bn (£3.19bn).While market chatter had recently suggested that Anglo was preparing to make a rival offer, reports in the Wall Street Journal say that Anglo a deal had been rejected on valuation grounds, saying that the price was too high.By 13:15 on Friday, Anglo's shares were 1.85% down at 2,440p.The FTSE 100 firm has been the centre of other coal-related M&A speculation in recent days. On Wednesday, reports in the Times suggested that the company is be considering an offer for US coking coal miner Walter Energy.Anglo is rumoured to be pitching an offer price at $120 per share for Walter, a massive 60% premium to its closing share price of $74.99 on Tuesday on Wall Street, valuing the US firm at around $7.49bn. BC