Chinese enterprises should proactively participate in pilot carbon emission trading systems (ETS) and regard it as an opportunity to develop their businesses, a report by US accounting firm Ernst & Young (E&Y) said on Monday.

With China planning to expand its pilot carbon ETS on a nationwide scale in its new five- year plan starting 2016, such involvements could prove to be beneficial, the report said.

Companies must learn about the details for monitoring and reporting mechanisms on their carbon emission and energy usage status, in order to sustain their competitiveness in the future, Chen Xiaoyan, director of Climate Change and Sustainability Services at E&Y, told a media briefing on Monday.

Rather than watching the pilot scheme as it gets underway, participating actively in the program could help the companies, she said.

China has pledged to reduce the amount of carbon dioxide produced per unit of GDP by 40 to 45 percent by the end of 2020 compared with the level in 2005.

The National Development and Reform Commission issued tentative ETS regulations in June 2013 and launched pilot programs, which will last to 2015, in the cities of Beijing, Tianjin, Shanghai, Chongqing and Shenzhen, as well as in the pro­vinces of Guangdong and Hubei.

However, short-term observation has indicated that corporate enthusiasm has fallen below expectations, the website of China Business News reported Monday.

Vague definitions in environmental pro­perty rights have reduced the effectiveness of the ­government's stimulus policies, Shen Xiaoyue, a senior official from the Ministry of Environmental Protection, said in a seminar held by E&Y on Monday. An inadequate market-oriented pricing scheme has also dented the willingness of companies to take part in the pilot program, Shen said.