Mumbai, Aug 9 (IANS): The selling spree continued at Indian equities markets Tuesday with a benchmark index falling over 550 points in opening trade as global markets shed heavily over the US sovereign debt downgrade.

The 30-scrip sensitive index (Sensex) of the BSE, which fell 558 points soon after opening, recovered a bit but was still trading with a loss of 428.43 points or 2.52 percent at 16,561.76 points.

The 50-scrip S&P CNX Nifty of the National Stock Exchange was also trading in the red at 4,981.45 points, down 2.68 percent.

Broader markets too were weak. The BSE midcap index was ruling 2 percent down and the BSE smallcap index was trading 2.1 percent down.

The market breadth at the BSE was negative with just 136 stocks moving up, compared to 1,360 on the decline and 39 remaining unchanged.

Other major Asian markets too were losing heavily, tracking the huge losses overnight at Wall Street and despite efforts by policymakers around the world to restore confidence in financial markets.

The benchmark Japanese Nikkei was down 4.14 percent, the Chinese Shanghai Composite index was ruling 1.19 percent lower, while Hong Kong's Hang Seng had fallen a huge 5.55 percent Tuesday.