BusinessAfrican oil explorer Impact Oil & Gas mulls biggest float since slumpExploring a float: Impact is set to list in LondonTodd Korol/ReutersJamie Nimmo20 July 2016An African oil exploration company has set in motion plans to float in what would be London’s biggest oil listing since the crisis bit in 2014.Surrey-based Impact Oil & Gas, which has assets off the coasts of Gabon, Namibia, and South Africa, is understood to be speaking to potential advisers about a float, likely to be on AIM.The plans coincide with Impact hiring Standard Chartered’s former heavyweight oil adviser Geraldine Murphy as a non-executive director last week. Sources said it was the first step towards an IPO, expected towards the end of the year. Murphy advised Cove Energy on its £1.2 billion sale to Thailand’s PTTEP.In 2014, Impact sold a third of the company to London-based Helios Investment Advisers, an African-focused private-equity firm, and a black economic empowerment investment firm for $55 million.The float is expected to value Impact at more than £100 million, making it the biggest oil listing since Nigeria’s Seplat went public in April 2014 with a £1 billion valuation. Seplat’s move came two months before Brent crude peaked at $115 a barrel before going into freefall.Impact declined to comment.MORE ABOUTfloatIPOAIMlistingOilBrentprice