East Africa’s biggest ever initial public offering (IPO) kicked off on Monday, as Kenyan operator Safaricom began trading on the Nairobi stock exchange.

The government’s sale of a 25 per cent stake in the carrier has proved popular, with the listing more than 400 per cent oversubscribed. Local reports suggest around 800,000 domestic and foreign investors had signed up to the offer.

The government is raising about $833m from the sale, which values Safaricom at around $3.3bn. In the first hours of trading shares had already gained around 50 per cent.

Post offer, the government holds 35 per cent of the company, with market partner Vodafone retaining 40 per cent.

Safaricom dominates the Kenyan market with a subscribers base of over 10 million at the end of March. It’s two rivals trail by a long margin, with Celtel boasting around 1.7 million users and Telkom reporting only 296,000.