Mumbai: The rupee fell by 18 paise to 56.29 against the U.S. dollar in early trade at the Interbank Foreign Exchange market, extending its losing streak for the fourth straight session as the American currency gained strength against other currencies overseas.

Forex dealers said besides dollar's gains against euro in the overseas markets on worsening euro-zone debt crisis amid growing fears that Spain may need a full bailout, a weak opening in the stock market also put pressure on the local unit.

The rupee had ended lower by 14 paise at 56.11 against the dollar 24 July vdue to continued dollar buying by importers.

Meanwhile, the BSE benchmark Sensex fell by 68.24 points, or 0.40 percent, at 16,849.84 in early trade.

According to the analysts, factors like RBI policy and reforms together with global signals will influence the market further.

The NSE index came down to 5099.60 with a drop of 28.60 points or 0.56 percent. The maximum and minimum in the same day were 5,121.60 and 5,096.30 respectively.

Similarly the 30-share Sensex saw a drop of 97.94 points or 0.58 percent. Its highest value was 16,899.01 and its lowest value was 16,802.03.