National Grid is to sell its UK wireless business to Arqiva, a subsidiary of Australia’s Macquarie Bank, for £2.5 billion.

National Grid Wireless is a major provider of infrastructure to mobile operators in the UK, with almost 14,500 sites. Its infrastructure is used by the BBC, Vodafone, T-Mobile, 3, O2, Orange, BSkyB, Channel 4, ITV and Emap.

The business has been seeking to make itself a key shared network service provider for converged networks to support digital television, digital radio, mobile broadband, mobile digital television and other mobile communication services.

The sale of the wireless business was part of National Grid’s strategy of focusing on its core UK and US electricity and gas markets, chief executive Steve Holliday said. The company is expected to similarly offload its US wireless business.

Arqiva – formerly known as NTL Broadcast – is the BBC’s preferred supplier for distribution and transmission. But the deal is expected to require approval by the Competition Commission, because Arqiva and National Grid each own around half the transmission masts used by UK TV and radio stations.