Africa Finance Corporation has invested in Dangote Petroleum Refinery’s $2.5 billion private placement, extending a financing relationship that began with a $300 million loan used to help develop the industrial complex.

The infrastructure financier said on Thursday that it led a group of strategic investors into the placement, the refinery’s first equity capital raise involving investors outside its legacy ownership.

AFC did not disclose how much it invested, the number of shares it acquired or the size of its resulting equity interest. The entire $2.5 billion was raised from a wider group of investors and should not be presented as AFC’s investment alone.

The deal nevertheless marks a new phase in AFC’s relationship with the refinery. The institution initially supported the project with debt and working-capital financing but has now invested through a private placement of shares.

The placement attracted international and African institutional investors, sovereign-linked investment vehicles, development finance institutions and strategic partners. Demand reached 3.7 times the initial offer size, according to AFC.