FTSE 100 mining group Anglo American has seen shares surge higher after receiving a £31.1 billion takeover approach from rival BHP Billiton in a potential mining mega-deal. UK-headquartered Anglo America’s shares shot up by as much as 14% in morning trading on Thursday after revealing overnight that Australia’s BHP – the world’s biggest miner – had put forward the “unsolicited” and “highly conditional” takeover proposal. Anglo said its board was reviewing the approach with its advisers. If it goes ahead, the deal would be another blow to the London stock market, with the loss of Anglo American from the top tier of shares and another FTSE 100 mainstay. Under the potential deal, BHP said it would offer £25.08 a share, including £4.86 a share in Anglo Platinum stock and £3.40 in Kumba Iron Ore company shares. The takeover would create the world’s biggest copper miner, with around 10% of global output. It would boost BHP’s presence in the burgeoning copper market, which is seeing demand soar amid the shift towards clean energy, as well as giving it greater access to potash, and coking coal in Australia. Copper is particularly sought after, as the metal is used in renewable energy projects...