NEW DELHI: State oil marketing companies on Tuesday raised the price of petrol by Rs 2 a litre, the biggest increase in nine months in Delhi, as international gasoline rates have surged and the rupee has depreciated following unrest in Iraq.Companies also increased the price of diesel by about 56 paise in the Capital as their revenue losses on the fuel have increased to about Rs 3.90 per litre from Rs 1.62 in the previous fortnight, government and industry officials said. All-India price increase is Rs 1.69 per litre on petrol and 50 paise on diesel, but the impact of the hikes would differ in different cities because of local levies, an executive in IndianOil said."Due to geo-political unrest in the Middle East, there has been significant increase in international oil prices during the past two weeks," the company said in a statement.The price of Brent crude oil , a widely-used international benchmark , had risen to $115 per barrel due to tension in Iraq. Prices have now fallen to $112.50 but the average price of Indian imports during the last fortnight is still higher than the previous two weeks.Oil marketing companies, which enjoy freedom to peg pump prices of petrol with international gasoline rates, wanted a steeper increase in petrol price , but they settled for Rs 2 a litre hike this time due to political reasons, industry sources said.Although petrol prices were deregulated about four years ago by the UPA regime, the oil ministry has tacit control over pricing of the fuel, and oil companies informally consult the ministry in pricing decisions. Companies usually avoid increasing petrol prices during assembly or Lok Sabha elections.The average price of international gasoline benchmark has risen by over $4 per barrel in the last 15 days and the local currency has depreciated by about 90 paise, making imported oil even more expensive in rupee terms.Oil companies price petrol on the basis of the landed cost of gasoline after accounting for notional freight and Customs duty. The price of petrol was last increased by about 75 paise on March 1 this year. Subsequently, fuel rates were reduced by about Rs 1.75 paise during the general elections, in April.Recently, companies silently raised its price by 15 paise in two installments without specifying reasons. Currently, petrol costs Rs 71.56 a litre in Delhi.