Telecoms equipment provider Ericsson has agreed a £30 million contract with Cable & Wireless to supply the company with GSM mobile network base stations.
Using equipment supplied by Ericsson, Cable & Wireless plans to supply fixed-mobile convergence (FMC) services to corporate customers.
FMC allows calls made from a mobile phone handset to switch between a cellular network and a VoIP (voice over internet protocol) network.
When FMC users are inside or nearby their work building, mobile phone calls are routed through a small, low-power GSM base-station that transfers the calls to a low-cost VoIP service.
Away from work, calls are routed through standard national GSM networks.
Earlier this year Cable & Wireless announced that Tesco would be its first FMC customer.
The supermarket chain store is paying £100 million for Cable & Wireless to completely overhaul its telecoms network.
Cable & Wireless bought a GSM license for FMC services in 2006, costing the company £50,000.