China National Petroleum Corporation secured a large gas supply deal with QatarEnergy on Tuesday, to ensure sufficient gas supply in the country.

The two parties signed a 27-year agreement, under which China will purchase 4 million metric tons of liquefied natural gas (LNG) a year from the Gulf Arab state. CNPC will also acquire a 1.25 percent share in the expansion of Qatar's North Field East LNG project, CNPC said in a statement on Tuesday.

According to CNPC, Qatar is the world's top LNG exporter while the North Field LNG project is the world's largest single gas field. Its expansion project includes gas field development and the construction of four LNG production lines, with a production capacity of 8 million tons per year.

It will produce an additional LNG production capacity of 32 million tons per year after put into operation, making Qatar's LNG annual export capacity increase to 110 million tons, it said.