The rupee continued to depreciate against the US currency in early trade following a firm dollar in overseas markets and sustained unwinding dollar-negative positions by dealers.
In generally weak trade at the Interbank Foreign Exchange (Forex) market, the Indian unit opened low at 46.55/56 per dollar as against Wednesday's close of Rs 46.5250/5350.
It moved down further to quote at Rs 46.5625/5725 per dollar in late morning deals.
The dollar on Wednesday initially showed a weak trend but recouped all its losses later.
Reduction in dollar-negative positions and mounting concern over Iran's nuclear activity all contributed to the dollar's strength, analysts said.
Slow down in foreign institutional investors (FIIs) portfolio investments for the last few days also weighed negatively on the rupee.