Agriculture Minister Sharad Pawar has asked Finance Minister P Chidambaram to give a 'second thought' to the budget proposal for commodity transaction tax (CTT) - a move that has agitated exchanges and the regulator."I wrote to him (Chidambaram) saying till the time we take a decision, hold it and give a second thought," he told PTI when asked whether the proposed levy would make futures trading more expensive and if he wanted it to be removed.The proposed CTT of 0.017% had prompted sharp reaction from all the three major exchanges and also the commodity regulator who had jointly petitioned Pawar saying it would sound the death-knell for futures trading.Pawar disagreed with the view that futures trading was leading to rise in prices of commodities saying the government has not seen any impact on prices of commodities that were banned for futures trading.Asked if there was a proposal to ban futures trading of essential commodities, Pawar said the issue was raised in Parliament and a committee under the chairmanship of Abhijit Sen was appointed. "We banned (last year) some items. We have banned pulses, rice and wheat, but we have not seen any impact on prices after the ban. Our observation is after liberalisation has been accepted in our country, prices are not just decided here," Pawar said.