About 45.89 million telecom subscribers have opted for mobile number portability (MNP), the technology that permits user to change operators while retaining their mobile numbers, as on the end of April 2012, a rise from 41.88 million users in March.
Karnataka received the maximum number of requests at 5.11 million, according to data released by the Telecom Regulatory Authority of India (TRAI).
Andhra Pradesh with a 4.44 million users opting for MNP was in the second position, while Gujarat with a 4.23 million requests ranked third.
MNP was introduced across the country in January 2012, with the pilot launch of the service in Haryana on 25 November 2010.
The number of telephone subscribers in the country rose 0.16 per cent, a meagre growth compared with that of previous months, taking the total subscriber base to 952.91 million as on April 30, 2012.
The total user base in the country, which is fastest growing telecom market in the world, stood at 951.34 million as on March 31, 2012.