O2, the UK arm of Telefonica's telecommunications service, said full-year revenues fell by 0.5% in 2013, as final quarter revenues for mobile services fell 6.1% year-on-year to £1.12bn.
The £200m sale of O2's home broadband business to Sky last May helped O2 achieve some gain, giving O2 an OIBDA of 7 per cent year-on-year.
The company also managed to add 983,000 net contract customers, which was its best contract performance for four years.
About 222,000 of those additions were in the fourth quarter, the eighth successive quarter in which O2 has added over 200 thousand net contract customers.
O2 Refresh, the contract service which lets customers upgrade handsets whenever they want, was a key driver for the success in customer contract additions, said O2.
Another 56% of new contract customers in the fourth quarter chose O2 Refresh taking the number of customers on O2 Refresh to 1.1 million.
Ronan Dunne, CEO of Telefónica UK, said: "Putting customers first has always been at the heart of everything we do. We continue to offer our customers unique services and they are rewarding us with their loyalty and satisfaction."
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