(IDEX Online) - Blackstone, the world's largest alternative asset manager, is reportedly poised to buy IGI (International Gemological Institute) in a deal worth up to $550m.Fosun International Ltd, one of the first enterprises in China to develop overseas markets, bought an 80 per cent stake in the network of 20 grading labs and 14 gemology schools back in September 2018 for $108.8m.Roland Lorie, whose father Marcel founded the company in Antwerp in 1975, remained at the helm and retained a 20 per cent stake.Blackstone, the New York-based investment manager with $991bn of assets, is now expected to sign an agreement in the next day or two, according to The Economic Times, to acquire the company.It says the deal will be worth $500m to $550m and reports that IGI owes its lenders $150m.Rumors of a possible IGI sale first surfaced in January, with Bloomberg reporting that the Fosun conglomerate, backed by Guo Guangchang, one of China's richest men, was in talks with Deutsche Bank AG.It said Fosun was seeking to shed a total of $11 bn of assets in a move aimed at boosting investor confidence.IGI describes itself as "the world's largest independent laboratory for testing and grading gemstones and fine jewelry".We have approached IGI, Fosun and Blackstone for comment.Pic courtesy IGI