Vodafone’s strategy of seeking to boost growth by expanding its presence in emerging markets took a big step forward last night when it announced a R22.5bn ($2.5bn) offer for a controlling stake in Vodacom, South Africa’s biggest mobile phone operator.

A deal would see Vodaphone, which has a 50 per cent stake in Vodacom, buy a 15 per cent stake from Telkom, the South African state-controlled telecommunications company that owns the other half of Vodacom.