BEIJING - China National Petroleum Corp. (CNPC), the country's largest oil and gas producer, said Thursday that its domestic natural gas output reached a record high at 103.3 billion cubic meters in 2017.

The amount was 5.3 percent more than 2016, and the first time that the oil and gas giant's annual natural gas output had reached 100 billion cubic meters.

The over 100 billion cubic meters of natural gas accounted for 70 percent of China's total domestic natural gas output and 44 percent of consumption in 2017, the company said.

The increasing natural gas production came against the backdrop of China's campaign to combat air pollution.

The 103.3 billion cubic meters of natural gas could replace 133 million tonnes of coal, which will result in a cut of 142 million tonnes of carbon dioxide emission and 2.2 million tonnes of sulfur dioxide emission, the CNPC said.

Currently, natural gas makes up 46.4 percent of CNPC's total oil and gas production, becoming a new growth point for the company.