LONDON, April 9 (Reuters) - EE, Britain’s biggest mobile operator, is on track to sign up 1 million customers for its 4G service by the end of the year, and is doubling connection speeds in 10 cities to encourage more people to make the switch, it said on Tuesday.

The joint-venture, owned by France Telecom and Deutsche Telekom, gained a head start on rivals in the 4G race when it re-used its existing airwaves to launch services last October.

Telefonica’s O2 and Vodafone, second and third in the market in terms of customer numbers, plan to roll out 4G in the next few months using airwaves sold by the government in February.

EE, which is charging about a 10-20 percent premium for 4G, refused to reveal customer numbers before the spectrum auction had ended, saying such data could influence bidding.

Chief Executive Olaf Swantee said on Tuesday that 4G had been well received by customers, and take-up of the service was running ahead of levels seen in other countries.

“Typically one in four new customers and new connections, both in B2B (business to business) and consumer, are on 4G,” he said. “Our plan is to deliver over a million customers on 4G by Christmas this year.”

That represented around 8 percent of the group’s contract customer base after 14 months, he said, against a 10 percent conversion rate after 24 months that the industry viewed as a successful launch in other countries.

Swantee said EE would double the speed of 4G in 10 cities by the summer, resulting in top speeds of 150 Mbps, and average speeds of more than 20 Mbps.

The faster speeds, made available by increasing the 1800 MHz airwaves dedicated to 4G, would make downloading high-resolution video easier and enable better multi-tasking on the latest smartphones and tablets, he said.

Birmingham, Bristol, Cardiff, Edinburgh, Glasgow, Leeds, Liverpool, London, Manchester and Sheffield will be the first cities to be upgraded, the company said.