In order to mitigate losses on sale of petrol, oil marketing companies have suggested the government to either declare it as a regulated product temporarily and provide subsidy for under recovery or reduce excise duty on the fuel. In a written reply in the Lok Sabha today, Minister of State for Petroleum and Natural Gas R P N Singh said the public sector oil marketing companies have not revised the price of petrol since December last despite sharp increase in international prices of petroleum products. He said, there is an under recovery of over seven rupees per litre on sale of petrol. Mr Singh said public sector oil marketing companies have incurred revenue loss of 138,541 crore rupees during 2011-12, which is 77 per cent more than the under-recovery of 78,190 crore rupees for 2010-11.