Competition for opportunities in Africa's increasingly crowded telecoms market is about to get tougher.

The chief executives of Vodacom, South Africa's leading mobile company, and Telkom, its biggest fixed-line operation, have ambitions to expand across Africa, potentially spurring a period of consolidation in the continent's fragmented markets. They hope to challenge the dominance of MTN, sub-Saharan Africa's leading mobile company with more than 55m subscribers across 16 countries.