The rupee on Friday breached the 74-mark against the US dollar for the first time as the Reserve Bank of India announced its key policy rate would remain unchanged.

The rupee was quoted 55 paise lower at 74.13 against the dollar soon after the RBI announced its monetary policy, reported PTI. The central bank retained the repo rate unchanged at 6.50 per cent, while the reverse repo rate also stayed at 6.25 per cent.

At the Interbank Foreign Exchange (Forex) market, the rupee opened higher at 73.56 a dollar against its previous record low closing of 73.58 on Thursday, but failed to sustain the initial strength and fell back to breach the 74 mark.

Meanwhile, the BSE Sensex too plunged by 584.53 points, or 1.66 per cent, to 34,584.63 in late afternoon trade.