New Delhi, April 10 :    New Delhi, April 10:  Nortel Networks, the troubled telecom networking giant, is looking at big business opportunities in Calcutta and will target companies in the city which might be interested in its voice over Internet protocol (VoIP) infrastructure - a new pasture in the telecom sector that was thrown open to everyone from April 1. On April 17, Nortel executives will descend on Calcutta to scout for business opportunities. The largest interest group is the call centres that are sprouting in the Salt Lake Electronics complex. The networking company is taking on Cisco, its main competitor, in areas like VoIP, call centre solutions, security and optical ethernet. At present, the company has a presence in Calcutta only through its channel partners - Compaq and Wipro. 'We have received many queries from Calcutta and other places in the eastern region like Guwahati and Jamshedpur for our products. The majority of the queries relate to setting up of call centres. There is a huge potential for call centres,' said Sanjay Jotshi, country manager, Intelligent Internet, Nortel Networks. 'We will also target major oil companies in the city along with the government sector in addition to telecom carriers. The east has been slow to join the IT revolution in the country but we are witnessing a steady growth and also an interest by state governments,' he added. The company plans to give special emphasis on VoIP and has launched a product that aims to reduce operating costs by up to 60 per cent. These will enable the carriers to deploy and manage new revenue-generating metro services. Nortel does business in more than 150 countries.