Mumbai: The BSE benchmark Sensex fell by over 55 points in early trade on Thursday, extending Wednesday's losses on continued selling by foreign funds and retail investors disappointed by the lacklustre first quarter earnings of some companies amid weak cues from global markets.

The 30-share barometer, which lost 151.49 points in Wednesday's session, moved down further by 55.41 points, or 0.30 percent, to 18,446.97 within minutes of the opening bell on Thursday, with stocks of auto, healthcare, realty, IT and metal companies remaining under pressure.

Similarly, the wide-based National Stock Exchange Nifty index shed 23.75 points, or 0.43 percent, to 5,543.30.

Market experts said the trading sentiment remained bearish amid a subdued trend on other Asian bourses, tracking overnight losses in the US market.

In addition, lower-than-estimated earnings by some companies and interest rate hike worries also dampened the trading sentiment, they said.

In the Asian region, Hong Kong's Hang Seng index was trading 0.20 percent lower and Japan's Nikkei shed 0.12 percent on Thursday morning. In the US, the Dow Jones Industrial Average ended 0.12 percent lower in Wednesday's trade