The Civil Aviation Ministry will hold discussions with the Home Ministry on the issue of pending dues worth over Rs 600 crore owed by Delhi airport operator DIAL to the CISF, a senior official said today. Against the backdrop of huge outstanding dues, the Home Ministry has written to the Civil Aviation Ministry warning that the CISF security cover for the airport could be withdrawn by year-end if the dues are not cleared, sources said. The Delhi International Airport Ltd (DIAL) operates the national capital's aerodrome, which is also the busiest in the country. "The Civil Aviation Ministry will be discussing the matter with the Home Ministry regarding the security provisions, treating it as a sovereign function," Civil Aviation Secretary R N Choubey told PTI. According to officials, the Civil Aviation Ministry is looking at possible funding from the exchequer and other options to help DIAL in clearing the outstanding dues. The Home Ministry officials said it was open for discussions with the Civil Aviation Ministry on the pending dues but made it clear that even the central government entities like NTPC, CIL and BHEL were regularly paying their dues for providing security to their installations. "Wherever there is sovereign duty, we are committed to provide security but otherwise entities which avail CISF services have to pay," one of the officials said. Passenger Service Fee (PSF) of Rs 154 is collected from each passenger flying out of the Delhi airport and part of the amount is set aside for security component. When contacted, a DIAL spokesperson said that security-related expenses of the airport are met from an escrow account which has money collected as PSF. "The security of Indira Gandhi International Airport is a sovereign function as per the State Support Agreement (SSA) signed with the government," he said. DIAL is working in a fiduciary capacity on behalf of the Indian government and is collecting the PSF from embarking passengers as per the tariff decided ten years ago, the spokesperson said, adding that the entire collection is passed to an escrow account. "Due to the cost exceeding the collection over a period of time, there is a deficit in PSF (Security Component) account. DIAL management had a meeting with ADG CISF (Airports) in the recent past and apprised him about the reasons for the deficit in PSF (SC). We are coordinating with Ministry of Civil Aviation to make sure that this issue is addressed," he said. The Central Industrial Security Force (CISF), which comes under the Home Ministry, guards around 59 civil airports in the country and charges a security fee in lieu of protecting these sensitive facilities against terror and sabotage threats. In March this year, the CISF had said that the DIAL's pending security fee amount was about Rs 737 crore. While the current dues could not be immediately ascertained, it is estimated to be more than Rs 600 crore.