Etihad Etisalat, which trades as Mobily, has increased its market share to nearly 40 per cent from less than 30 per cent a year ago.

The company’s only rival, the former monopoly Saudi Telecom, had already announced that it had 17 million customers at the end of 2007.

“Our forecast for Etisalat was 7.2 million, but it’s almost doubled,” says Joss Gillet, an analyst at Wireless Intelligence, part of industry trade body the GSM Association.

Etihad Etisalat only reveals its customer numbers once a year, while Saudi Telecom updates the market every quarter. The Saudi division of Etisalat had just 6 million customers at the end of 2006.

Both Etihad Etisalat and Saudi Telecom will have to compete with Zain, the Kuwaiti operator, when it starts offering mobile phone services in Saudi Arabia in June 2008.