The rupee weakened by 7 paise to Rs 45.55 a dollar in early trade at the Interbank Foreign Exchange on Thursday amid mild demand for the American currency and dollar gains overseas.

Forex dealers said besides dollar demand from importers and its gains against other currencies, a weak opening in the stock market also weighed on the rupee sentiment.

The rupee had depreciated by 18 paise to Rs 45.48/49 against the US currency in the previous session.

Meanwhile, the Bombay Stock Exchange benchmark Sensex fell by 47.73 points to 17,545.04 points in opening trade on Thursday.