BEIJING - The US mining equipment maker, Joy Mining Machinery, plans to build its second factory in China in the next five years, aiming to push further into China's fast-growing coal market.

Lou Boltik, global marketing manager of the Pennsylvania-headquartered cost effective mining equipment producer, told China Daily that the investment of the proposing factory would be $80 million or more.

"China is our major focus, because the country is the biggest market for underground coal mining and our mining equipments are primarily for underground mines," Boltik said at the China Coal and Mining Expo 2011, which ended in Beijing on Monday.

He refused to offer detailed plan of the investment, saying they haven't decided the specific location of the factory.

As the largest coal producer in the world, China produced nearly half of the world total with around 3.2 billion tons of coal in 2010, out of which 90 percent was from underground, according to Boltik.

"The United States produced around 1 billion tons in 2010, only 35 percent of that was from underground, so you can see how important Chinese market is for us," he said.

The global sales of Joy Mining Machinery were around $2.5 billion in 2010 and its home market, the United States, contributed around $1 billion.

The sales in China have been growing at 20 percent to 25 percent a year, the total sales in China is expected to reach 400 million this year, said Boltik.

He said that China market has a lot of opportunities and how to keep up with the growth in China is his company's major challenge in the country.

Joy Mining Machinery has been selling its products to high-productivity coalmines in China since 1980s. Its first factory in China was built in Tianjin in 2008.

The company has a service center in Baotou, North China's Inner Mongolia autonomous region, and its second service center in Baotou is under construction.

Joy Mining Machinery belongs to Joy Global, which is one of the world's leading heavy-equipment mining companies. Joy Global bought an initial 41 percent stake in China-based International Mining Machinery Holdings Ltd for $585 million to expand in Chinese coal market in July this year.

IMM is a leading designer and manufacturer of underground longwall coal mining equipment in China with revenue of approximately $299 million in 2010.

"A core part of our business strategy has been to position ourselves for the high growth of the emerging markets, and the investment in IMM is a major step in the execution of that strategy," Mike Sutherlin, President and Chief Executive Officer of Joy Global, told Reuters in July.