PetroChina on Thursday reported that 2012 net profit fell 13.3 percent, despite increased production, as the oil giant was hit by a slowdown in the growth rate of the Chinese economy.

China's largest listed oil company said its 2012 profit was 115.33 billion yuan ($18.56 billion), down from the 132.96 billion yuan it recorded in 2011. Revenue rose 9.6 percent to 2.2 trillion in 2012.

PetroChina saw an increase of 4.5 percent in barrels of oil and natural gas equivalent output for 2012, compared with 2011. Its refineries experienced a rise of 2.8 percent in barrels of crude oil for the year.

"In the face of the complicated and harsh economic environment both domestically and abroad in 2012, the company strenuously endeavoured to transform the mode of its development and focused on the quality and efficiency of its growth," PetroChina said in a statement.

The company also attributed the reduced profits to "macro regulation and control" of domestic refined oil along with lower domestic prices for sales of imported natural gas.

Chinese leaders cut refined oil product prices last May and June in line with weaker international crude prices, squeezing the profit margins of domestic refineries.

China's energy firms were hit last year by a slowdown in the world's number two economy and biggest commodities consumer, owing to a steep fall in overseas demand for its crucial exports.

The Chinese economy expanded 7.8 percent in 2012, its worst performance in 13 years, due to weakness at home and in key overseas markets after the nation saw a growth of 9.3 percent in 2011 and 10.4 percent in 2010.