Billionaire Aliko Dangote is seeking to raise $1.6 billion in what would be Nigeria’s biggest initial public offering, selling shares in the company that operates Africa’s largest oil refinery. Dangote Petroleum Refinery and Petrochemicals FZE is offering 4.1 billion shares at 525 naira ($0.40) each, a company spokesman said Friday. The IPO will open on Sept. 14.

Nigeria’s Securities and Exchange Commission approved the sale on Friday, according to Director-General Emomotimi Agama. The much-anticipated IPO values the refinery at about $49 billion, according to data provided by the company. The sale will help fund a near-doubling of the plant’s capacity from 700,000 barrels a day.

It comes as Nigerian equities are surging, with the benchmark index up 72% in dollar terms this year, making it the world’s best-performing stock market. Built at a cost of about $20 billion, the facility reached full capacity weeks before the Middle East conflict intensified concerns about global fuel supplies. It has become a major source of refined products in the region and beyond, including supplying jet fuel to Europe.