The Vodafone Group is increasing its investment in its Ghana Telecom arm to $700 million (£459 million), $200 million (£131 million) more than previously planned.
The network said the further investment was made to ensure quality in the expansion plans.
Vodafone spent $900 million on a 70 per cent stake in the Ghanaian firm last August. It previously said it would invest a further $500 million over five years.
Vodafone Ghana spokesman Ben Padovan said: “We decided to increase the investment in order to effectively improve network quality and undertake quality expansion.”