A growing number of scientists and engineers who have worked abroad are seeking business opportunities in China after encountering career barriers overseas.

More than 200 overseas Chinese and representatives of 30 associations for Chinese abroad attended the two-day Conference on China International Exchange of Professionals at the Shenzhen Convention and Exhibition Center, which ended on Thursday.

Some of them, who still had luggage with them, rushed to the venue in the morning eager to discuss project proposals with potential investors and partners.

Hui Wenhua was one of them. He has worked for an electronic chemical company in New Jersey, United States, for 18 years, climbing the ladder from researcher to chief scientist in the research and development department. The 62-year-old said he is not ready to retire.

"After reading media reports about severe chemical pollution in China, I realized that I can help with my expertise," he said.

The expert on chrome plating — a technique of electroplating a thin layer of chromium onto a metal or plastic object — said most workshops in China still use a conventional technique that contaminates the environment and increases workers' risk of lung cancer and leukemia.

"Many companies in China dump pollutants secretly, because they don't want to invest in pollution treatment to save money," he said, adding that there are numerous unregistered workshops apart from the thousands of registered ones.

Hui said the technique being used in the US, which he can help introduce to China, generates no pollution. It also saves on costs, energy, and improves product durability.

"About 15 people, including government officials and bosses of private companies, have shown interest in my business proposal," he said.

Hui said investment of 80 million yuan ($13 million) is needed to introduce the technique from the US and bring his team of five researchers to China.

Nicole Wu, a consultant at the North America Chinese Scholars International Exchange Center, said China has been viewed as an ideal place by increasing numbers of overseas Chinese to start a business thanks to its huge market and favorable government policies.

The exchange center, which is registered in the US and acts as a bridge between that country and China, organized the pavilion at the Shenzhen conference dedicated to overseas Chinese starting careers in China.

Most of those wanting to start a career are men in their 40s and 50s with a science and technology background, Wu said.

Rock Lau, assistant general manager at the Shenzhen branch of the Beijing Foreign Enterprise Human Resources Service, the conference co-organizer, said many overseas Chinese professionals encounter "glass ceilings" in their careers.

"For many Chinese scientists and engineers in Western countries, even those with achievements in their fields, their career paths are restricted to research," he said.

However, China is in great need of applied science in environmental protection, information technology, new materials and energy, and medical skills, so overseas Chinese with relevant expertise have an advantage, Lau said.

Zheng Mingjie, from Jilin province, went to Nagoya in Japan in 1990 for his PhD studies in engineering, settling there with his family and working as a researcher for an energy conservation design company in 1996.

Zhang planned to start an energy service company in China last year by sending his business proposals to local governments and venture capital companies in the country, but the competition for funding proved fiercer than he expected.

"I sent my proposal to a business plan competition staged by the government of Jiaxing, in Zhejiang province, but it did not pass the first round of 700 applications because I don't have the patent for the energy-saving technology," the 59-year-old said.

Zhang expected investment of 16 million yuan to set up his company. However, Chinese banks prefer to grant loans to projects that win government business plan competitions, while venture capitalists favor projects that generate quick money.

During the conference in Shenzhen, venture capital investors pledged financing of about 20 million yuan for 50 projects.

Most overseas associations also reached initial agreement for cooperation with domestic organizations, according to statistics released by the organizing committee.

The conference was staged by the State Foreign Expert Affairs Administration and the Shenzhen government.

On Wednesday, the Shenzhen government offered 40 million yuan in seed funding for 122 entrepreneurs who have studied overseas to start businesses in the southern city.

It has emerged as one of the most popular destinations for entrepreneurs who were educated overseas. Low business rents, seed funding and favorable tax policies have helped professionals to start businesses there.

The organizing committee says Shenzhen has 1,700 companies run by former students who returned from overseas. Almost all are high-tech companies, with about 30 firms having annual output worth more than 100 million yuan.