(Reuters) -- Everything Everywhere, Britain's biggest mobile carrier, expects to start building a next-generation LTE network by the end of the year, catching up with the United States and parts of Scandinavia and Asia that already have more advanced networks.

Everything Everywhere, a joint venture of France Telecom and Deutsche Telekom, is likely to be the first of Britain's carriers to deploy LTE, as it already has radio spectrum it can use for the new, faster services.

Rolling out the fourth-generation (4G) network is dependent on approval from regulator Ofcom, which must sanction the use of the 1800 MHz spectrum for a purpose other than the one for which it was granted.

Everything Everywhere is hopeful Ofcom will give its approval by April or May, allowing it to proceed on schedule with the new network, which promises connection speeds many times faster than current, third-generation networks.

It is planning Britain's first LTE trials over 1800 MHz in the western English city of Bristol starting in April.

We expect a small-scale commercial launch with focus on mobile broadband, initially. We'll further expand in 2013 as more devices become available, Chief Executive Olaf Swantee told journalists at a briefing.

There is so far a limited number of phones that are compatible with LTE technology.

Ofcom is also preparing for an auction of spectrum that will be awarded specifically for 4G services, amid wrangling among the operators over the terms. Britain's other carriers are Vodafone, O2 and Three.

Everything Everywhere is spending 1.5 billion pounds ($2.4 billion) on upgrading its network.

(Reporting by Georgina Prodhan; Editing by Elaine Hardcastle)