The number of cellphone users who have chosen to avail mobile number portability has hit the 10 million mark in about four and-a-half months since the national launch of mobile number portability or MNP, an official in sector regulator TRAI told.

Initial results have clearly established an underlying trend that incumbent GSM biggies, led by Vodafone Essar, have been the biggest gainers under this facility. As on May 24, Vodafone has recorded a net gain of 591,600 new customers followed by the Aditya Birla Group-owned Idea Cellular (590,343) and Bharti Airtel (563,460).