BEIJING — Chinese authorities are stepping up their antipiracy campaign, raiding 14 factories running disc-copying businesses around the country in the last week, stripping six of their operating licenses and halting production at the rest, state media reported.

News came as U.S. Commerce Secretary Carlos Gutierrez said China was the biggest loser from intellectual property violations and needed to fight piracy to become a global player.

Gutierrez was on a trip to the southern city of Chongqing to prepare for Chinese president Hu Jintao’s state visit to Washington, D.C., next month.

The crackdown is part of a campaign that started in January. Officials checked 48 disc-copying businesses across the country and found 14 were operating illegally.

China’s disc-copying industry accounts for around one-fifth of the world’s recorded discs, an official with the State Administration of Press & Publications told the Xinhua news agency.

Despite efforts by Hollywood studios to make legal DVDs of films more widely available in China, authorized versions still are hard to get. Chinese people tend to either download movies from the Internet or buy them openly in illegal stores.

Piracy remains a key irritant to trade relations between Beijing and Washington, and many U.S. lawmakers blame it for a portion of the trade deficit with China, which hit a record $202 billion last year.

U.S. movie, software and other copyright industries estimate they lose more than $2.5 billion annually in China due to piracy.

The Chinese government has been keen to highlight its efforts to stamp out the trade in fakes and insists China’s improved legal framework, protection mechanisms, antipiracy campaigns and publicity are reaping dividends.

In 2005, Chinese courts prosecuted more than 3,500 criminal cases involving infringement of intellectual property, up 28% from the year before, and punished 5,336 people, up 30% from the previous year, said the Supreme People’s Court.

In January, trade officials in Washington asked China to prove it is serious about combating piracy, and officials said the U.S. could bring a case against China to the World Trade Organization if it fails to provide convincing evidence of its antipiracy credentials.

The Bush administration vowed last month to get tough with China on trade and IPR issues.

Gong Zheng, deputy director of China’s General Administration of Customs, said Monday that 1,210 piracy trade cases involving $12.3 million were cracked last year, 90% of them related to exports. These cases included goods as well as DVDs and CDs.

Gong said customs have confiscated 210 million pirated discs shipped in from foreign countries since 1999 and arrested 2,119 suspects for IPR violations in 2005, a rise of 56% from a year before.