New Delhi: Telecom operator Bharti Airtel Friday announced closing of 3G service in Kolkata as part of its plan to replace the third generation mobile technology with 4G in the country.”This is in line with our stated strategy of focusing on serving quality customers with best-in-class service experience. Going forward, we plan to refarm all of our 3G spectrum across India and deploy it for 4G in a phased manner,” Randeep Sekhon, CTO Bharti Airtel said in a statement. Also Read – Maruti cuts production for 8th straight month in SepIn Kolkata, Airtel will use 900 Mhz frequency band for 4G service which was earlier being used for 3G. “Airtel has refarmed the 900 Mhz band spectrum being used for 3G to further strengthen its 4G network. The company is deploying state-of-the-art L900 technology in the 900 MHz band to complement its 4G service in the 2300 Mhz and 1800 Mhz bands,” it said. Airtel claimed that with L900 technology, its smartphone customers will enjoy improved 4G service. “Airtel will continue to provide 2G service in Kolkata to serve the connectivity needs of customers on feature phones. All customers on 3G were duly notified and requested to upgrade their handsets/SIMs to continue enjoying best-in-class smartphone experience. Also Read – Ensure strict implementation on ban of import of e-cigarettes: revenue to Customs”3G customers who are yet to upgrade their handsets/SIMs will continue to get access to high quality voice services,” Airtel said. In London, Shares of Bharti Airtel’s Africa arm began trading at the London Stock Exchange Friday at 80 pence apiece. The initial public offer, to raise up to USD 750 million, was oversubscribed with strong interest from a variety of reputed global investors across the UK, US, Africa, Europe, Middle East and Asia, Bharti Airtel said in a regulatory filing. The company has put 744,047,619 new shares on offer, out of which 94.7 per cent of the stocks will be listed on the London Stock Exchange (LSE) and rest in Nigeria. “The Offer also came with a secondary listing on the Nigeria Stock Exchange with meaningful allocations to Nigerian investors,” it said. Trading for institutional investors began Friday, while retail investors can start trading in the shares from July 3 in the UK, and from July 5 in Nigeria.