Mr Stephen Brewer, chief executive of Eircell, the Republic's largest mobile phone network, will step down next month and assume the position of managing director, Vodafone UK sales and distribution.

Mr Brewer will be replaced at the start of October by Mr Paul Donovan, current managing director, commercial, at Vodafone UK, who has assumed the title of Eircell chief executive designate.

Mr Brewer's appointment comes just months after Vodafone acquired Eircell.

He will head a team of 3,000 people in the UK at a time when Vodafone's UK operation is struggling to retain market share.

The most recent mobile phone penetration figures for the UK marketplace show that Vodafone has slipped behind Orange and BT Cellnet in customer numbers.

"It VODAFONE UKis very successful, but it's now a question of looking after the customers you've got," said Mr Brewer yesterday.

"I want to bring customer retention management with me to the UK."

"The things we've done in Ireland with Eircell have always been first, or near-firsts in Europe," he said. "To be successful in Ireland you have to work hard due to the small scale of the country."

Mr Brewer joined Eircell as Chief Executive in 1995 during the lead up to liberalisation in the Irish mobile market.

Over the past few years, Eircell has managed to retain an impressive 60 per cent share of the market. However, Mr Brewer said his replacement at Eircell should attempt to reinvent the business and make a conscious effort to become part of the business community.

Mr Donovan, the new chief executive designate at Eircell, has been a senior executive with Vodafone Group since October 1999. Prior to this he worked with Cable & Wireless.