Mumbai, Apr 12 (IANS): Ahead of the release of data on factory output and retail inflation, key Indian benchmark indices opened flat on Tuesday, even as other Asian markets showed a somewhat mixed trend with Japanese benchmarks up and those in China trading lower.

The sensitive index (Sensex) of the BSE opened a tad higher at 25,056.47 points, against the previous close at 25,022.16. Minutes after, the key index of 30 shares was ruling at 25,074.97 points, up 52.81 points or 0.21 percent.

At the National Stock Exchange, where the Nifty had closed the day before at 7,671.40, the opening bell saw the index at 7,669.25 points. Soon after, the index was ruling at 7,685.55 points, up 14.15 points or 0.18 percent.

On Monday, the Sensex ended with a gain of 348.32 points or 1.41 percent, while the Nifty was up 116.20 points or 1.54 percent. Last week while the BSE bellwether fell 596 points or 2.35 percent, the NSE's 50-share benchmark lost 157.85 points or 2.04 percent.

The breadth of the market was so positive on Monday that 46 out of the 50 Nifty stocks ended with gains. At the BSE, 26 shares were up and four were down -- three of them from the pharmaceuticals sector.

"After failing to sustain an early upside move, US stocks ended mostly unchanged on Monday. The pullback came as investors remained cautious ahead of first-quarter company earnings,"Angel Broking said, ahead of market-opening in India.

"Japanese Yen showing continued strength may have also weighed on the markets. The European markers recovered well and ended in the positive zone after a weak start," the brokerage said, attributing the gains to factors like gains in Italian banks and rising metal prices.