China's coal consumption posted steady growth in the first three quarters, with an increase of thermal coal consumption in late September after three consecutive months of decline, according to the country's top economic planner.

China consumed 2.28 billion metric tons of coal in the first nine months, up 10.3 percent year-on-year, the National Development and Reform Commission (NDRC), China's top economic planner, said in a statement on its website Thursday.

Coal shipped via railway and ships in the first three quarters totaled 2.17 billion metric tons, according to NDRC.

As the world's largest coal producer and consumer, China relies on coal to fuel its economy as about four-fifths of electricity comes from thermal power plants.

In terms of inventory, coal stocks at five major ports expanded by 980,000 metric tons from the end of September to reach 12.51 million metric tons on Oct. 18.

Major thermal power plants added 6.31 million metric tons to their coal reserves, bringing the current total to 70.86 million metric tons, which can meet electricity generation demands for an average of 20 days, said NDRC.

Coal imports surged 25.1 percent from a year earlier to 19.12 million metric tons in September, reversing a decline in coal imports in the first eight months.

China's imports grew 1.9 percent year-on-year to 123 million metric tons from January to September, while exports totaled 12.12 metric tons in the period.

According to the NDRC data, China has become a net importer of coal in the first nine months, with a net import of 111 million metric tons.