KARACHI, Nov 26: Differences among mobile phone operators over the share of investment needed to constitute a board to implement mobile portability number (MNP) is causing delay in its implementation, well-placed sources in the telecommunication sector said.

All the six cellular mobile operators have formed a supervisory board or a numbering council headed by Telenor CEO Tore Johnsen and a representative from the Pakistan Telecommunication Authority to implement the MNP technology, according to the telecoms regulator.

However, the sources said, the major mobile phone operator -- Mobilink -- possessing the largest number of subscribers -- appeared reluctant to make a proportionate investment to implement MNP as the company feared losing its customers.

All the companies had to invest to install MNP technology as per their market share on the basis of the number of subscribers, they added. MNP is a system which enables a mobile phone subscriber to change his service provider while keeping the same phone number and service code.

In a meeting last month, the mobile phone operators pledged to overcome their differences and put in place the much-awaited MNP system by the end of January next year.

The cellular mobile policy approved by the federal cabinet in January 2004 had mandated the introduction of MNP by December 2005, but the deadline lapsed. The latest deadline of October 31, 2006, has also lapsed.

In July this year, PTA Chairman Shahzada Alam Malik impressed upon the mobile phone operators and the PTCL the need for speeding up the process of upgrading their switches for the early implementation of MNP.

However, the sources said that the deadline was once again extended by January next year without taking any action against the operators.