India’s top telecommunications carrier, Sunil Mittal-led Bharti Airtel Ltd, reported its 11th consecutive quarter of profit decline as costs increased and a slowdown in customer additions limited revenue growth.

Bharti, controlled by billionaire Mittal, said on Wednesday that consolidated net profit fell 29.8 percent to 7.21 billion rupees ($132.5 million)for its fiscal second quarter ended September from 10.27 billion rupees a year earlier. Analysts had expected net profit of 7.46 billion rupees.

Bharti and its main rival, the local unit of Vodafone , are set to benefit after a court revoked the permits of several smaller rivals, which will cut the competition in a market that once boasted more than a dozen players.

The leading carriers, however, face the risk of paying out billions of dollars in regulatory fees over the next few years with the government planning to impose a surcharge on airwaves held by them and also because of reallocation, or switching, of their superior quality spectrum when their permits are renewed.

Bharti, nearly a third owned by Southeast Asia’s top phone carrier, Singapore Telecommunications Ltd, operates in 20 countries across Asia and Africa and is the world’s fourth-biggest mobile phone carrier by customers.

The Sensex today dropped by nearly 130 points to close at 18,675.18 on lower-than-expected Infosys earnings and a cut in its full-year sales guidance, amid slowing industrial production growth in August.

The BSE benchmark index opened nearly 78 points lower dragged down by Infosys scrip which tanked nearly 8 per cent on reports the IT major’s July-September quarter revenues and profits failed to beat share market expectations.

Infosys posted 24.3 per cent jump in consolidated net profit at Rs 2,369 crore while its revenues were up 21.7 per cent at Rs 9,858 crore. The scrip pared some losses to close at Rs 2,395.65, down 5.36 per cent.

The Sensex, which had climbed 174 points in the previous session, closed lower by 129.57 points, or 0.69 per cent to 18,675.18. Infosys, Wipro and Bharti Airtel were major losers.

Brokers said market sentiment was hit due to a cut in Infosys’ profit margin and sales outlook. Infosys lowered its revenue growth guidance for the current financial year to 17.3 per cent from the earlier target of 19.7 per cent, setting off alarm bells.

“It was a down day for markets…for fourth quarter in a row, Infosys’ stock crashed post results. Infosys guided about challenging times and trimmed down its FY13 guidance,” said Nagji K Rita, CMD, Inventure Growth & Securities.