Dangote Refinery, Nigeria’s first indigenous refinery, has signed an agreement with its financial advisers, including Stanbic IBTC, Vetiva Advisory and FirstCap Limited, ahead of the launch of what is described as the biggest initial public offering in Africa.

Dangote Refinery seeks to raise $1.6 billion by selling 4.1 billion shares at $525 ($0.40) between September 14 and October 13, according to the signed prospectus. Dangote pegged the minimum quantity of shares that can be purchased at 10.

“The refinery means too much to our continent,” said Aliko Dangote, head of Dangote Group. “We can’t industrialise it if we don’t have energy security.”

The IPO has already raised $2.5 billion from an early-entry private placement that set a minimum investment amount of $350,000 for ultra-wealthy investors at about ($0.35).

African Finance Corporation and African Export-Import Bank were among the private placement investors.

The Dangote Refinery has also been praised by Europeans, who said the African petroleum exporter helped ease fuel supply pressures triggered by the U.S.-Iran conflict.