Earlier reports from India said MTNL was planning to bid as high as 160 million dollars for the telco.
The latest report quoting an un-named source said MTNL had submitted a bid between 100 to 120 million US dollars.
Sri Lanka's John Keells Holdings and Telecom Malaysia -- which runs the island's largest celco Dialog -- were also in the running for the firm earlier in the year but the 160 million dollar tag was considered pricey when the first round of bids closed.
Dialog, which owned a fixed wireless license, has since started to deploy its own network.
Telecom analysts said with Dialog entering the fray the value of the telco was "not what it was before". MTNL has now become almost the last serious contender for Suntel.
Indian reports said MTNL also had a Sri Lanka partner.
Suntel officials had said earl