The company had in February announced that it would buy the business and assets of Loop Mobile in Mumbai under a strategic agreement.
The company, however, is yet to get the regulatory approvals for the agreement.
"With reference to the earlier announcement dated February 18, 2014 titled 'Airtel and Loop Mobile announce agreement to create Mumbai's largest mobile network', Bharti Airtel Ltd has now informed the BSE that the Company has signed the definitive agreement with Loop Mobile (India) Limited," Airtel said in a filing to the BSE.
As per market estimates, the agreement is worth Rs 700 crore though the company did not disclose the size of the deal.
Under the agreement, Loop Mobile's 3 million subscribers in Mumbai will join Airtel's over 4 million subscribers, making it the largest network in the metropolitan city.
Loop Mobile's 2G-enabled network supported by 2,500 plus cell sites have also become part of Airtel's network which has over 4,000 cell sites at present.
The agreement will ensure continuity of services to the subscribers of Loop Mobile, whose licence is expiring in November this year, with an option to access Airtel's services.