At the interbank foreign exchange market, the rupee posted a strong gain of 225 paise–its biggest single-day gain in at least 15 years–to end at 66.55 against the dollar, on thursday. The rupee rose after the Reserve Bank of India eased pressure in the currency market by starting a facility for state-run oil refiners to buy foreign exchange. Dollar sales by exporters on expectations of a further rise in the rupee also lifted the local currency.