At the interbank forex market, the domestic unit opened at 72.90 against the US dollar, then lost further ground and touched 72.92, registering a fall of 23 paise over its previous close.
On Tuesday, the rupee had settled at 72.69 against the American currency.
Meanwhile, the dollar index, which gauges the greenback's strength against a basket of six currencies, advanced 0.17 per cent to 90.66.
"FPI flows into the domestic markets could cap the depreciation bias of the local unit," Reliance Securities said in a research note.
Meanwhile, Asian currencies are weak this morning and could weigh on sentiments, the note added.
On the domestic equity market front, the 30-share BSE benchmark Sensex was trading 325.12 points lower at 51,779.05, and the broader NSE Nifty declined 89.40 points to 15,224.05.
Foreign institutional investors were net buyers in the capital market as they purchased shares worth Rs 1,144.09 crore on Tuesday, according to exchange data.
Brent crude futures, the global oil benchmark, advanced 0.17 per cent to USD 63.46 per barrel.