The first carbon permits in Shanghai traded at 27 yuan ($4.85) on Tuesday, as the financial hub launched China's second such trading scheme in a bid to cut its fast-growing greenhouse gas emissions.

Three trades for a total of 9,500 permits for 2013 compliance, known as Shanghai Emissions Allowances (SHEAs), went through in the first half-hour after the market opened. A third carbon market will open in Beijing on Thursday.

China is the world's biggest emitter of greenhouse gas emissions, but it has pledged to reduced its emissions per unit of GDP to 40-45 percent below 2005 levels by 2020.

Bin Hui, vice director at the Shanghai Environment and Energy Exchange, told reporters that state-owned power company Huaneng was one of the companies involved in the Tuesday deals, but gave no further details.

The opening price matched the first trades that went through when the Shenzhen emissions market opened in June, but prices there have since risen to around 60 yuan.