The New Zealand sharemarket started the day firmly, as key stock Fletcher Building pushed up to 900 for the first time in nearly three years.

Around 10.20am the benchmark NZX-50 index was up 7.64 points to 3394.88, on top of a gain of 11.5 points yesterday.

Fletcher Building was up 5c early to 900, Ebos Group lifted 5c to 750, Pumpkin Patch added 2c to 131, Contact Energy was up 2c to 580, and Sky TV lifted 2c to 555.

The dual-listed banks had a good start to the day with ANZ up 25c to 3176 and Westpac up 20c to 3200.

Stocks declining early included Fisher & Paykel Healthcare, down 5c to 309, and Port of Tauranga down 2c to 789.

In the United States, stocks advanced as optimism about upcoming earnings and investor buying of the quarter's top performers lifted the Standard & Poor's 500 Index above a key technical level.

The S&P 500 broke above its 50-day moving average at 1305, leading investors to believe the market may have absorbed the worst of its recent pullback caused by Japan's earthquake and tumult in the Arab world, positioning stocks for another move higher.

The Dow Jones industrial average gained 0.7 percent to 12,170.56, the S&P 500 climbed 0.9 percent to 1309.66, and the Nasdaq Composite Index rose 1.4 percent to 2736.42.

Semiconductor stocks were among the best performers and helped boost the Nasdaq after Micron Technology Inc posted a quarterly profit that topped Wall Street's forecasts.