"MTNL has decided to introduce unlimited free local calling for its landline and broadband customers (Combo) between 2200 HRS to 0700 HRS to any network. The free unlimited calling facility is also available for Delhi MTNL landline customers to any network to Mumbai and vice versa during the same hours," it said in a statement.
The STD call charges have also been made local by making call charges rate at 180 sec/pulse, it added.
According to data from telecom regulator Trai, MTNL had 11.4 lakhs wired Broadband service subscribers as of February this year.
India's telephone (wireline) subscriber base stood at 2.67 crore at the end of February 2015 of which MTNL accounts for over 35 lakh subscribers.