The rupee depreciated by 14 paise to 79.66 against the US dollar in opening trade on Thursday, tracking the strength of the American currency overseas.

At the interbank foreign exchange market, the rupee opened at 79.55 against the greenback, then fell further to 79.66, registering a decline of 14 paise over its last close.

On Tuesday, the rupee had finished at a nearly two-week high of 79.52. The domestic forex market was closed on Wednesday on account of Ganesh Chaturthi.

Meanwhile, the dollar index, which gauges the greenback's strength against a basket of six currencies, rose 0.28 per cent to 109.

The rupee opened weaker against the dollar as prospects of further aggressive policy tightening by the US Federal Reserve and the European Central Bank (ECB) weighed on Asian currencies and equities, said Sriram Iyer, Senior Research Analyst at Reliance Securities.

"Oil prices remained subdued this Thursday and could cap losses, but weak Asian and emerging market peers will cap gains," Iyer said, adding the range for the rupee in this session is 79.30 to 79.75.

The global oil benchmark Brent crude futures fell 2.84 per cent to USD 96.49 per barrel.

On the domestic equity market front, the 30-share BSE Sensex was trading 683.03 points or 1.15 per cent lower at 58,854.04, while the broader NSE Nifty was down 189.55 points or 1.07 per cent to 17,569.75.

Foreign institutional investors turned net buyers in the capital market on Tuesday as they purchased shares worth Rs 4,165.86 crore, as per exchange data.