The chairman of the Public Accounts Committee Dr Murli Manohar Joshi on Monday said that the panel will take an appropriate decision to have interaction with the Prime Minister at an appropriate time. He was speaking to reporters after the meeting of the Committee.In reply to a question, Dr Joshi said that the CAG calculated the loss to the exchequer due to 2G spectrum allocation according to the best system practised by world over. He said that the CAG, Vinod Rai elaborated the technical details of the calculation during his interaction with the committee. Dr Joshi said that the costs may go up or down keeping in view the three different ways of calculation.Dismissing media reports that the CAG was summoned to the panel, Dr. Joshi said that he is a part of Public Accounts Committee.He said the public accounts committee has received the Prime Minister's letter voluntarily expressing his readiness to appear before it. AIR correspondent reports, Dr Singh in his letter has said that if the committee wants any clarification form him, he is ready to give. The Prime Minister had also at the Congress plenary last week declared that he was prepared to appear before the PAC since he had nothing to hide.CAG in its report tabled in Parliament said there is a presumptive loss of over 1.76 lakh crore Rupees to the exchequer in the spectrum allocation. The issue led to stalling of the entire Winter session of Parliament with opposition pressing for a JPC Probe. AIR correspondent reports, under Speaker's direction 99 under the rules of procedures and conduct of business in Lok Sabha, the PAC cannot call a minister to give evidence or for consultations in connection with the examination of accounts by it. The chairman of the committee, however, may have an informal talk with a minister on the subject under consideration by the committee. Since the Prime Minister's offer is unprecedented in its nature, the Speaker may have to devise a procedure on how the committee could accept the Prime Minister's offer of appearing before it.The PAC will continue with its examination of the controversial allocation of 2G spectrum. The committee has already obtained some information from the Department of Telecommunications, the Finance Ministry, the Telecom Regulatory Authority of India and experts in the telecom sector. According to a Lok Sabha Secretariat notification, the PAC had also sought views from the general public.