Kolkata: Petrol prices rose by Rs 3.14 and diesel by Rs 3.11 per liter as of Friday morning. The new prices have increased the concerns of drivers, transporters, and small businesses across the country. The step as been taken to help the oil marketing companies combat huge under recoveries. According to Nischal Singhania, former president of the Delhi Petrol Dealers Association, oil companies sent information about the new rates to petrol pump operators late last night, which went into effect Friday morning.