India, April 21 -- Operators of truck fleets across India are bracing for fuel rationing and the first major rise in diesel prices in years, a move that would end a period of relative stability that has continued even into a war in the Gulf. The world's third-largest oil importer is among the countries most exposed to the trade upheaval in the Middle East as the conflict extends into an eighth week-but it has not faced the widespread price hikes at the pump seen elsewhere, as the government shields consumers and state-run refiners absorb losses. That may be about to change, once key regional elections wrap up next week, as pressure increases and the war drags on. A hike by those state-owned refiners would add to inflationary pressures weighing on the economy. Truck drivers already report widespread informal rationing that forces them to stop more frequently to fill their tanks, delaying deliveries. "We are going to see an increase in diesel prices after the elections," said Shailendra Gupta, an executive member at All India Motor Transport Congress, a truckers' lobby group. "Already nearly 10% of the fleet is idle, if the fuel prices are increased that number could go up to 30%." Pumps have withdrawn discounts they used to give earlier on monthly purchases above a certain threshold, he said. Private players like Nayara Energy Ltd have already raised pump prices and Reliance Industries Ltd and its partner BP Plc have rationed supplies. Still, any widespread increase in retail fuel prices, coupled with a weak exchange rate, would feed through to the wider economy. Ajay Bansal, president of All India Petroleum Dealers Association, said there was currently no rationing at state outlets- though they were feeling the knock-on effect from other restrictions....