Oil prices fell further in Asia today to a five-year low, continuing a steep sell-off sparked by Organization of Petroleum Exporting Countries, OPEC's decision to maintain crude output in an over supplied market. The unabated price plunge comes after OPEC opted on Thursday to maintain its collective output ceiling at 30 million barrels per day, where it has stood for three years.US benchmark West Texas Intermediate for January delivery dipped $ 1.55 in early Asian trading to $ 64.60, its lowest intra day level since July 2009. Brent crude for January sank $ 1.84 to $ 68.31, below the psychologically important $ 70 level.