Bharti Airtel on Friday, slashed mobile roaming tariff by almost 60 percent, giving an indication that the tariff war is not over yet.

The announcement hastened losses in the shares of Bharti,. The stock fell as much as 3.3 percent but trimmed losses to 2.7 percent at 284.90 rupees by 0825 GMT in a Mumbai market that was up 0.3 percent.

The price war, aimed at acquiring new users ahead of fresh entrants waiting in the pipleline, has raised worries about telecom firms' profitability. Four new companies, including ventures funded by Telenor and Etisalat, are ready to start services this year adding to the existing 11 operators.

Bharti's market value has fallen more than a fifth this year to about $24 billion and its stock is the second worst performer in the main index that has risen about 72 percent. Rival Reliance Communications has fallen about a quarter in 2009.

Bharti, whose about 115 million users account for more than 23 percent of India's total mobile users, in September slashed call charges within its own network to 50 paise a minute and launched a low-profit per-second billing plan in October.

Tata Teleservices was the first to launch per-second billing, contrary to the industry norm of per-minute billing. The offer was a huge success and the firm has topped the new signings for three months in a row.

Bharti's latest offer will permit users to receive calls at 60 paise a minute while roaming, and they can make calls at 60 paise a minute within the Airtel network and at 80 paise a minute for calls to other networks. Bharti has said it will be competitive in pricing but had no plan to match the lowest price in the market.