NEW DELHI: To counter competitors, state-run BSNL today announced a national unlimited 3G mobile data plan for Rs 1,099 and doubled the data usage limit in some existing plans."Due to improvement in network, BSNL has been gaining customers. We are now first in the industry to offer unlimited 3G plan for Rs 1,099 without reduction in speed. This will rejoice our customers and help them experience improved BSNL networks," BSNL Chairman and Managing Director Anupam Shrivastava said.BSNL added most number of subscribers in April for a third month in a row, as per data released by telecom regulator Trai.Growth in mobile segment in April was led by BSNL which added 11.39 lakh subscribers followed by Bharti Airtel (9.78 lakh), Aircel (5.72 lakh), Reliance Communications (1.1 lakh), Vodafone (46,600), Quadrant Videocon group firm - 25,012) and MTNL (11,591).To counter private telecom operators' strategy of slashing data rates by up to 67 per cent, BSNL has doubled data usage in Rs 549 plan for 3G service to 10 GB from 5 GB."The plan has validity of 30 days and is equivalent to 100 per cent increase in data benefits to subscribers," Shrivastava said.The telecom firm has doubled 3G data usage in Rs 156 plan to 2 GB which will be valid for 10 days."Last year, BSNL had also facilitated the customer by offering 80 per cent cheaper voice tariff. By massive reduction in data tariff and introduction of unlimited data STVs (Special Tariff Vouchers), BSNL hopes to serve data customers, mainly the youth segment in a much better way," BSNL Board Director (CM) RK Mittal said.In July, private telecom majors -- Bharti Airtel, Vodafone and Idea Cellular -- increased data usage limit in some of their 3G/4G plans by up to 67 per cent to counter threat from Reliance Jio which is offering 90 days free unlimited data and phone call service.