China's anti-piracy bureau on Thursday denied reports it is investigating possible monopoly behaviour of large software companies including Microsoft Corp.

China's State Intellectual Property Office said in a notice that it was not conducting any investigation and such reports were "seriously untrue."

The state-run newspaper Shanghai Securities News reported Wednesday that the office was investigating alleged monopolistic practices of large software companies such as Microsoft and that local companies might file antitrust lawsuits under a new law taking effect Aug. 1.

"Our office has never conducted research on monopoly behaviour aimed at any enterprises," the notice said. "And at present we have no plan to conduct this work," it said.

A Microsoft spokesman, Ranfeng Chen, said the company supports efforts to establish an environment conducive to promoting fair competition and said Microsoft is in compliance with Chinese law.

"We also believe efforts such as the anti-monopoly law will better safeguard interests and benefits of consumers, encourage innovation and enhance economic development," he said.

The report in the Shanghai Securities News said the investigation would focus on discriminatory pricing of software and the use of a monopoly position in operating system and office software to sell more software and limit space for development of domestic companies.

While not mentioning Redmond, Wash.-based Microsoft by name, the report quoted a source that named the company.

It cited an unnamed "authoritative source" as saying that the cost of a Microsoft Windows system, which sells for 1,000 to 2,000 yuan ($147 to $295), and Office software, at 4,000 to 5,000 yuan, is higher than the cost of a computer.

It cited the same source as saying that it was "not normal" for a multinational company to use its dominant position to sell its legitimate software at extremely high prices while criticizing a public lack of respect for copyright protections.