BEIJING (XFN-ASIA) - The National Development and Reform Commission said it has approved the expansion of an ethylene project owned by Daqing Petroleum & Chemical Co, a unit of PetroChina Co Ltd.

The project in northeast China's Heilongjiang province will double its capacity to 1.2 mln tons per year, the top economic agency said in a statement.

It did not say when the expansion would be completed.

The project is part of the company's petrochemical development plan aimed at offsetting the effects on the local economy of declining oil output.

The Daqing field was first tapped in 1960 and accounted for around one-third of the country's oil production in 2002, but output has declined steadily in recent years.

PetroChina said earlier that the field produced 43.4 mln tons of crude oil in 2006, slightly lower than the 44.95 mln produced in 2005.