In any slum area, the Competent Authority may, with the previous approval of the State Government and on such terms and conditions as may be agreed upon, entrust to any agency recognised by it for the purpose,—
(a) the execution under its own supervision of any improvement, clearance or redevelopment works;
(b) the maintenance or repairs of any such works under its control;
(c) the work of collection of service charges recoverable by and due to it.]