State-run operator, MTNL triggered a fresh tariff war in the ISD services segment by slashing rates of calls to six countries, including US, Canada and China, for its GSM and 3G subscribers. Calls to these countries will now be charged at Re 1 per minute.

"We are expecting Rs 10-15 crore revenue addition through our ISD rate reductions, which -- in all -- include 26 countries through volume growth. About 1-2 lakh more subscribers are expected to add our existing 50 lakh user base on account of this," said MTNL CMD Kuldip Goyal.

Call rates to Hong Kong, Thailand and Singapore would also cost Re 1 per minute.

While an ISD call to China currently costs Rs 9.20 a minute, the same for Singapore, Hong Kong and Canada stands at Rs 6.30. The PSU has cut call rates to 26 countries in the range of Rs 6.30-Rs 18 per minute to Rs 1-Rs 5 per minute.

ISD calling rates to Argentina, Bahrain, Cyprus, Jordan, South Korea, Malaysia and Sweden would be reduced to Rs 3 per minute. The PSU has also cut the call rates for Australia, Austria, Bangladesh, Columbia, Indonesia, Iraq, Russia, Taiwan, Uzbekistan and Vietnam to Rs 5 per minute.