The number of people opting to switch mobile phone operator but keep their own number has increased dramatically in 2005.

Figures released by the Commission for Communication Regulation (ComReg) show consumers switched 94,000 mobile subscriptions in the first half of 2005 using the State's mobile number portability system. This compares to a churn rate of 62,000 mobile subscriptions in the first six months of 2004.

The portability system, first introduced in July 2003, allows mobile phone users to switch operators and take their old mobile phone numbers with them. Prior to the introduction of the mobile number portability system, Irish consumers had to change their mobile numbers if they moved between operators.

The inability to keep a number when switching mobile networks had been cited as a major disincentive for consumers and businesses looking to change their mobile phone provider.

Before the system was introduced the two biggest mobile firms, Vodafone and O2, held more than 95 per cent market share.

ComReg's latest mobile portability statistics show that 330,000 mobile subscriptions have been switched since the system was introduced to promote more competition in the mobile market.

A breakdown of the 330,000 subscriptions which churned between firms is not available. However, the third operator Meteor said yesterday it had benefited hugely from the system.

Andrew Kelly, Meteor's director of corporate affairs, said the firm had added three new customers for every customer that chose to leave Meteor under the system.

"Meteor is the only net beneficiary of the system," he said. "But our performance has increased dramatically since we launched our bill-pay product last month."

Under the terms of the agreement setting up the number portability system in 2003, no operator is allowed to disclose how many people have switched between the different mobile networks.

However, people who switch to the latest entrant to the Irish mobile market, 3 Ireland, cannot yet use the number portability system to retain their number.

"3 sees the full implementation of mobile number portability as critical, as it will mean a truly level playing field allowing Irish consumers to benefit from our competitive pricing without having to switch numbers," said the firm, which is in talks with ComReg and the other operators on extending the system shortly.

ComReg Commissioner Mike Byrne said mobile number portability in the Republic was leading-edge in terms of international practice.

The four Irish mobile phone operators have signed up 3.86 million subscriptions. This is close to the 3.9 million population of the Republic. It is estimated 84 per cent of the population now owns at least one mobile phone.