Last week's change of mobile phone codes cost Egyptian operator Etisalat LE60 million (US$6.4m), the company's executive director Salah Al-Abdouly said today.
Egyptian mobile numbers all became 11 digits in length on 6 October in a move decreed by the country's National Telecommunication Regulatory Authority (NTRA) to meet surging demand.
Etisalat Egypt, a subsidiary of the UAE's sole telecoms provider, put the LE60m cost down to updating its systems but said it may later announce a loss in revenue due to disruptions caused by the switch.
Talking to press on the sidelines of a conference in Dubai, Al-Abdouly also said his company intends to invest LE7 billion in its enterprises over three years starting in 2013.
The changes to phone numbers on 6 October varied according to network and opening digits, which led to some confusion among users.
Egypt's three mobile service operators -- Etisalat, Vodafone and Mobinil -- have launched advertising campaigns to raise awareness about the changeover among their estimated 76 million subscribers.
Previous numbers will continue to work for at least four months, with callers reaching a recorded message advising them to update the number before their call is connected.
Last week Amr Badawi, president of the NTRA, told Ahram Online: "We will be monitoring the situation. When we see people have changed to the new system we will announce the old numbers will be discontinued."
Many phone users are able to download a free application from their network that will automatically update the numbers in their phone address book.
Nevertheless, mobile firms are expecting the majority of users -- some 60 to 70 per cent -- to use less advanced methods such as asking local mobile shops to manually change the numbers.