The Chinese government treats companies equally regardless of their ownership as it investigates anti-trust behavior, a senior official said yesterday as he signaled an even tougher crackdown on monopolistic behavior may be planned as only "heavy punches will work" to halt a rise in corporate monopolistic behavior.

"It wouldn't be objective to say that the investigations target foreign firms because they involve foreign firms," said Xu Kunlin, head of the anti-monopoly bureau of the National Development and Reform Commission, China's top economic planning agency and price regulator.

Over the past months, the government has deepened efforts to investigate wrongdoings in several sectors from drugs to baby formula in the anti-monopoly campaign which has already ensnared some multinational companies.

Speaking at a forum in Beijing, Xu said that competition policy should become a key economic principle in China, and that only "heavy punches will work" to halt a rise in monopolistic practices by companies in the country.

Xu said last month that China could extend its anti-trust investigations to more industries such as petroleum, banking, automobile and telecommunications as they all have a direct impact on the lives of ordinary Chinese.

Last month, the NDRC fined a group of mostly foreign milk power producers a total of 668.8 million yuan (US$109 million) for price-fixing, including a 203.76 million yuan fine on US-based Mead Johnson Nutrition. The companies also agreed to cut prices.

Since China passed its landmark anti-trust law in 2008, the biggest fine imposed was on Kweichow Moutai Co, a leading luxury liquor maker, which was fined 247 million yuan for violating price monopoly regulations early this year.