New Delhi, March 19 : A Delhi court Tuesday summoned Bharti Airtel chairman Sunil Bharti Mittal, former telecom secretary Shyamal Ghosh and Essar Group promoter Ravi Ruia in a case relating to alleged irregularities in allocation of excess spectrum during the NDA regime.

Special Central Bureau of Investigation (CBI) Judge O. P.  Saini issued summons for April 11 after taking cognizance of the charge sheet filed against mobile firms Bharti Airtel, Vodafone and Sterling Cellular for alleged irregularities.

On Dec 21 last year, the CBI named Ghosh and the three telecom firms as accused in the charge sheet for criminal conspiracy and charges under provisions of Prevention of Corruption Act for causing a loss of about Rs. 846 crore to the national exchequer during the National Democratic Alliance (NDA) regime.

The agency told the court that additional spectrum was allotted July 17, 2002, to Bharti Cellular (now Bharti Airtel) and Sterling Cellular (now Vodafone Mobile Service) for the Delhi metro area, and Hutchison Max (now Vodafone India) for Mumbai metro area. (IANS)