Last month Bharti Airtel and Tata today announced that they have entered into an agreement to merge Consumer Mobile Businesses (CMB) of Tata Teleservices Limited (TTSL) and Tata Teleservices Maharashtra Limited (TTML) into Bharti Airtel. Today Airtel has announced that starting today, Tata Teleservices customers will start transitioning to the Airtel mobile network under an Intra Circle Roaming (ICR) arrangement.