3 UK and T-Mobile UK are close to completing their joint venture 3G expansion after their 10,000th cell site was activated last week.
3 started its 3G network expansion in January last year in concert with T-Mobile under a network share arrangement.
The project will have 13,000 sites when it concludes in October.
Cell site numbers have now increased from 6,000 at the start of last year to 10,000, with the latest being activated in Shooters Hill, South East London.
3 claims the increase in cell sites brings its 3G network population coverage to around 93 per cent in the UK, which it claims is the largest spread of coverage by headcount.
3 chief technology officer Graham Baxter said: “The continued growth of internet communications, smartphone use and mobile broadband uptake have brought the need for good 3G network coverage into sharp focus for millions of consumers.
“Our network is already the biggest 3G network in the UK. Now we’re adding new coverage and capacity across the country to meet demand and bring the benefits of 3G to people who’ve never had access in their area before.”