A benchmark index for Indian equities markets on Tuesday slipped in noon trade below the 18,000 points mark - for the first time in over five months - as selling intensified across the market breadth. The 30-scrip sensitive index (Sensex) of the Bombay Stock Exchange (BSE), which opened at 18,141.51 points, was ruling at 17,891.04 points -- down 146.15 points or 0.84% from its previous close at 18,037.19 points.

The Sensex slipped beflow 18,000-point mark last Aug 31 last year.

The 50-scrip S&P CNX Nifty of the National Stock Exchange was trading 0.91% lower at 5,346.75 points.

Broader markets saw heavier selling, with the BSE midcap index down 1.61% and the BSE small cap index trading 2.01% lower.

Consumer durables, realty and banking scrips were in the red, while IT stocks saw moderate gains.

The market breadth was negative, with 591 stocks advancing compared to 2,035 scrips on the decline. A total of 106 stocks remained unchanged.

The major gainers on the Sensex were Tata Power, Hindalco Industries, Bajaj Auto and Cipla. The losers included ONGC, M&M, Jaiprakash Associates and Tata Steel.

Other Asian markets were mixed as concerns over continuing political turmoil offset the positive sentiments, brought on by overnight gains on Wall Street.

The Japanese Nikkei moved up 0.41% to close at 10,635.98 points, while Hong Kong's Hang Seng was trading 0.56% down at 23,421.54 points.