The pay television and high speed Internet operator raised 130 million US dollars to finance its growth in east and southern Africa.
Richard Bell, Wananchi's vice chairman, said the company would invest the cash in expanding its fibre-optic network to cover more homes in more cities across the region.
"We will also invest in exciting new technologies and service platforms to improve the quality of our products," Bell said in a statement.
The capital investment was led by Wananchi's existing shareholders, including Altice and Liberty Global, as well as new investors, Helios Investment Partners.
Founded in Nairobi six years ago, Wananchi's Zuku brand covers a network of more than 200,000 homes in Kenya's capital Nairobi and its second city of Mombasa, the company said.
Demand for broadband and pay TV in east Africa has been growing in recent years in line with economic growth and increased urbanisation.