Africa's richest man, Aliko Dangote is extending the deadline for the initial public offering of his Nigerian oil refinery.

The IPO was due to close on Tuesday but will now be run until October 27th.

The 700,000 barrel-a-day Lagos facility had aimed to raise $1.6 billion to double its capacity.

Dangote says there's been enough interest to raise more than three or four times the target amount. The extension, he said, was to ensure ordinary people get a chance to own a stake in the refinery.

"We are going to extend the date because we want a lot of our African brothers and sisters to participate," Dangote told journalists during a tour of the facility on Monday. "It is not about the amount, it is about the number of people that we want to participate."

If the proposed expansion goes ahead, it will be the world's largest - surpassing India's Jamnagar.

Dangote has also just broken ground on a new facility on Kenya's Lamu island. He has promised the project will create tens of thousands of jobs, but is facing a lawsuit from the local community over land rights. Greenpeace has also raised objections over the refinery's environmental impact.