Shares jumped in early morning trading, adding $3.58, or 6.8 percent, to $56.03.

The Milwaukee company said steel production in China remained strong through April and is on track to jump 8 to 10 percent this year. Power production in China is up by about 20 percent from 2009, the company said.

It now expects to earn between $3.85 and $4 per share on revenue of $3.3 billion to $3.4 billion for the fiscal year ending in October. It previously expected net income of $2.85 to $3.05 per share on revenue of $2.8 billion to $3 billion.

The company also said that demand in the rest of the world is adding to already sizzling growth in China and India. That's helping boost prices for commodities such as coal, which is used to produce steel and electricity.

Joy Global said prices improved in all its regions during the fiscal second quarter that ended in April, but noted that North American improvement was "especially encouraging." U.S. coal producers are now exporting metallurgical coal, which is used to make steel, to China and India instead of solely to more traditional markets like Europe and Brazil.

Joy Global also said its second-quarter net income dipped slightly. The company earned $120.4 million, or $1.15 per share, compared with $120.5 million, or $1.17 per share, in the year-ago quarter. Revenue fell 3 percent to $896.2 million.

The results far exceeded Wall Street's expectations. Analysts surveyed by Thomson Reuters expected a profit of 77 cents per share on revenue of $754.8 million.

The company said there are signs that demand is beginning to level off in China, but said it should allow "more sustainable growth for the longer term." Joy Global predicts commodity demand will continue to grow over the next several years.