The CEOs of Shell and Dow Chemical, two oil and chemical giants in the world, have said they are willing to expand investment in China as the country is increasingly important on the global stage.

Peter Voser, chief executive office of Royal Dutch Shell, told Xinhua in an interview on the sidelines of the Annual Meeting of the World Economic Forum that Shell has significant investment plans in China, which is one of the company's key countries.

"We are very optimistic that we will achieve a very competitive position there," he said. "It is the biggest market in the world in the longer term and I think we have all the businesses and all the products which China will need."

Now Shell has closely cooperated with Chinese state-owned oil companies like CNPC and Sinopec. China is becoming the most important energy market, and the two (CNPC and Sinopec) are Shell' s partners in China, said Voser.

"They are very active in all the areas of upstream and downstream," he said. "We are very happy to collaborate and work together with them within China but also outside China. We are delivering our technology and our best products into China."

Andrew N. Liveris, CEO of Dow Chemical, also told Xinhua in a separate interview that China has created "amazing" new demand. " We see China as a manufacturing economy that has entered the world stage," he said. "It's obviously geared towards exports, but increasingly to local consumption."

Liveris said that the infrastructure investment made by the Chinese government was rapid and it has worked and created huge domestic demand.

He said Dow Chemical is now working on the Yulin project, a coal-to-chemical project in northwest China's Shaanxi Province, together with Shenhua Group, China's biggest coal producer.

Last year, Dow Chemical opened up the Shanghai development center, with 800 scientists inventing new technologies there. Liveris said this is "not just for China, but for the world."

He said that he wanted to tap the human intellect of big emerging countries. Operations in China, India, Brazil and the Middle East have accounted for 80 to 90 percent of its current total investment in the world.