NEW DELHI (REUTERS) - India's Supreme Court has asked a lower court to defer until April 22 a summons to Bharti Airtel Ltd Chairman Sunil Mittal in a case over alleged corruption in allocation of mobile airwaves, as it will continue hearing Mittal's plea seeking to have the summons overthrown.

The supreme court will resume hearing on Thursday Mittal's plea challenging the summons, judges said, after a hearing on Monday.

The case at the lower court over airwave allocations a decade back also involves former executives in two firms that are now part of Vodafone Group Plc's Indian unit.