Vodafone and Virgin Media O2 have announced a new extension of their existing network sharing agreement.

The pact, which was set-up in 2012 and would be extended by more than a decade, helped the roll out of 4G and 5G mobile broadband by allowing the firms to share equipment, such as radio antennas. Vodafone and Virgin Media O2 say the network sharing agreement helps boost mobile coverage for its tens of millions of customers.

But it comes as Vodafone and Three await the final outcome of their mega £15billion merger, which is currently being pored over by the Competitions and Markets Authority (CMA). Should the merger get the green light, it would allow Virgin Media O2 to acquire more "network spectrum" - which refers to radio waves used for communication purposes. A final decision from the CMA is due before the end of the year.

Ahmed Essam, chief executive of European markets for Vodafone, said: “With this agreement and our merger with Three, we will transform the mobile experience for over 50 million customers in the UK for the long-term, providing significant network improvements including more choice, better quality and greater coverage across the country.

“These benefits extend to both retail and wholesale mobile virtual network operators (MVNO) customers. The proposed merger, together with this agreement, will boost competition by establishing a strong third player in the UK mobile market and will improve the balance of spectrum holdings, levelling the playing field between the UK’s mobile operators.”

Lutz Schuler, chief executive of Virgin Media O2, said: “This new agreement with Vodafone ensures that quality mobile network choice, performance, coverage and competition is enhanced to the benefit of millions of consumers, businesses and our mobile operator partners across the country.

“We are extending and bolstering elements of our existing network-sharing arrangement, while also ensuring there is a robust, balanced and functional structure in place for the long-term should Vodafone and Three’s proposed merger gain consent. We believe that this new agreement addresses the issues we have voiced and the CMA outlined in its initial decision, and will now continue our engagement with the regulator in this spirit.”