Despite interventions from the RBI and the government, the rupee continued its free-fall mode, hitting a new record low of 64.54 against a dollar. The benchmark Sensex also slipped below 18,000 points mark for the first time in almost a year.The rupee, savaged by large dollar demands from banks and importers, has plunged to new lows for the fourth session in a row, while the Sensex has shed nearly 1,500 points. The last four sessions of slide has eroded almost 100 billion dollars of the Indian stock market's capitalisation. The partially-convertible rupee slipped to 64.54 against a dollar at the inter-bank foreign exchange market, surpassing its previous record low of 64.13 hit Tuesday.The Indian currency closed below 64 level against a dollar for the first time. It ended the day at a record low of 64.11 against a dollar, 86 paise lower than the previous session close at 63.25.The Sensex closed 340 points or 1.9 percent down at 17,906 points. The index has lost 1,450 points in the last four sessions.Nifty also ended the day sharply down for the fourth straight session. The Nifty declined 99 points, to 5,303.