Mobile phone retailers T-Mobile and 3 will pool their networks, in an initiative that has sparked speculation that the two rivals might merge.

T-Mobile and 3, the UK’s fourth and fifth biggest operators with about 250 UK stores each, plan to share their 3G networks to enable them to cut the costs of rolling out infrastructure across the uncovered parts of the country.

Hutchison Whampoa-owned 3 covers about 90 per cent of the UK population with its network, while T-Mobile covers about 84 per cent.

As the smallest UK player, 3 has long been expected to be the subject of a takeover as part of consolidation in the mobile market.

The UK is one of the most competitive mobile phone markets in Europe. Each of the five UK operators want to gain market share in a saturated market and cut churn.

Vodafone and Orange have announced a plan to share their networks in a deal to provide savings of up to 30 per cent.