Mobile operator O2 is to mount a legal challenge over Ofcom's decision to allow rival Everything Everywhere to rollout 4G this autumn.
Everything Everywhere recently got the go ahead from Ofcom to use its existing spectrum to run 4G services from 11 September, while its rivals will have to wait until next year.
This gives Everything Everywhere, which owns both Orange and T-Mobile, a 12-month head start on its competition.
According to report in the Guardian, Telefonica, the Spanish owner of O2, has written to Ofcom and warned it may be forced to take legal action to overturn the decision.
The company has also reportedly sent a copy of the letter to Culture Secretary Jeremy Hunt.
The operator could claim interim relief as part of the appeals process, which could also delay Everything Everywhere's 4G plans.
Both O2 and rival Vodafone have raised concerns about Ofcom's decision to give Everything Everywhere a head start on 4G, with the former claiming the move will exclude "the majority of consumers from the first wave of digital services". Vodafone is yet to announce any plans, if at all, to appeal.
An Ofcom spokesperson declined to comment on the O2 letter, but told IT Pro: "We are ready for any potential litigation of our decision to allow this and we will robustly defend our position if required."
