A benchmark index for Indian markets Wednesday gave up its intra-day gains and closed on a flat note as official data showing that quarterly economic growth for October-December quarter was at its slowest in three years dampened sentiments.

The 30-scrip sensitive index (Sensex) of the Bombay Stock Exchange (BSE), which opened at 17,919.93 points, closed at 17,743.6 points (provisional), 12.48 points or 0.07 percent up from its previous close at 17,731.12 points.

The Sensex had crossed the 18,000-mark in early trade.

The 50-scrip S&P CNX Nifty of the National Stock Exchange also ended similarly lacklustre at 5,383.5 points, up 8 points or 0.15 percent from its previous close.

Broader markets also saw gains being tempered, with the BSE 500 index closing 0.36 percent up. The BSE midcap index, however, rose 1.1 percent while the BSE smallcap index gained 0.68 percent.