In an announcement on Friday evening, Singapore's smallest mobile operator by subscriber base said that Mr Montefiore is quitting to 'pursue other personal interests'.

An engineer by training with over 30 years experience in the telecommunications, 56-year-old Mr Montefiore joined M1 in April 1996 and has been M1's public face since.

A year later, M1 launched its mobile service - breaking SingTel's monopoly over the Republic's telecommunications sector.

Under his watch, the upstart telco successfully made inroads into the mobile phone market, especially the youth market with its cheery and quirky marketing campaigns. This segment remains a core customer base. M1 also promised better service, launching a 24-hour customer service hotline, a first for the telecommunications market then. Just last June, Mr Montefiore was named Mobile Operator CEO of the Year Award by Asian MobileNews.

In a statement, Mr Montefiore said that it 'has been my great pleasure and privilege to have been intimately involved with the inception and growth story of M1. This period has been a tremendous source of pride and satisfaction for me personally and professionally and I will treasure all the memories and experiences I take away from the more than 12 years of close association with M1'.

Mr Montefiore declined to be interviewed.

Mr Montefiore, said M1 chairman, Mr Lim Chee Onn, 'has very ably led M1 from its launch in April 1997, through its public listing in 2002 and to its current strong position in the telecommunications market'.

M1's chief financial officer, Ms Karen Kooi Lee Wah, 53, will take over as acting CEO, while maintaining her current duties.

Read the full story in Saturday's edition of The Straits Times.