Mumbai: The Bombay Stock Exchange benchmark Sensex fell by 105 points in opening trade on Thursday, extending its losses on sustained selling by funds, tracking a weak trend in the rest of Asia.

The cautious approach adopted by participants, Thursday being the last session before monthly expiry in the derivatives segment, also pulled down the 30-share BSE index in opening trade.

The 30-share Sensex, which lost 78.01 points in the previous session, moved down further by 105.18 points, or 0.64 percent, to 16,340.84 in opening trade.

In a similar fashion, the wide-based National Stock Exchange Nifty index declined by 36.35 points, or 0.73 percent, to 4,909.55.

Stocks of metal, consumer durables, realty and auto companies remained under selling pressure and were mainly responsible for the Sensex's decline.

Market experts said sustained selling by funds in the absence of positive domestic cues amid a weakening trend on other Asian bourses following overnight losses in the US mainly dampened the trading sentiment here.

In the Asian region, Japan's Nikkei index was trading 1.02 percent down in early trade, while Hong Kong's Hang Seng index was closed after a typhoon alert was issued. In the US, the Dow Jones Industrial Average fell by 1.61 percent in the previous session.