To boost landline business, state-run telecom operator BSNL has announced unlimited free calling scheme during night hours from its fixed line phones to any operator including mobile phones anywhere in the country from May 1.

The scheme would be operational between 9 PM to 7 AM and would cover all type of connections, BSNL said in a statement.

"BSNL has introduced unlimited free calling during night hours from its landline phones to all landline phones and mobile phones of all service provider's network on all India basis from 1st May," BSNL said.

Under the scheme, all major landline general plans of rural and urban areas, landline special plans as well as all major combo (landline with broadband) plans are covered.

As per latest Trai data, BSNL which dominates landline market was the biggest loser of fixed-line customers in February while Airtel emerged as top gainer. The company had over 1.66 crore landlines at the end of February.

Even after losing 162,556 landline customers in February, the company dominated the market with 62.26% share.