MUMBAI - India's telecoms regulator said it would cut by up to 29 per cent the charges paid by mobile service operators to allow their customers to make calls to different carrier's networks, boosting shares of mobile firms.

The new port charges are about 23 percent to 29 percent lower than the present rates and will be effective from Apr. 1, the Telecom Regulatory Authority of India said on its Web site.

The cut will reduce operational costs for firms in the world's fastest-growing mobile market.

"There has been a long pending demand by interconnection seekers that port charges need to be reviewed," the regulator said.

"TRAI expects that service providers will pass the benefit of reduction in port charges to consumers," it said.

Shares in top mobile operator Bharti Airtel Ltd. rose to a record high, before ending up 5.4 percent at 771.05 rupees, while second-ranked Reliance Communications Ltd. also climbed to a new peak before finishing up 3.5 percent at 490.55.

Last month, the telecom regulator cut tariffs for national roaming on mobile networks by up to 56 per cent.