The companies were exposed by the General Administration of Quality Supervision, Inspection and Quarantine (GAQSIQ) on its official website, www.aqsiq.gov.

    "They will be banned from exporting food products," Lin Wei, an official with the administration, said here Tuesday.

    The substandard products, which included preserved seafood and fruit, were destined to be exported to Japan, Canada, the United States and the European Union, according to the administration.

    Some of the products were found to contain additives such as sulphur dioxide in excess of levels set by the importing countries, or were found to be contaminated by harmful bacteria.

    A total of 34,400 cases of fake and low-quality food have been cracked by China's industrial and commercial authorities in the first half of this year, involving goods worth 67.7 million yuan (8.9 million U.S. dollars).

    Sun Wenxu, an official with the State Administration for Industry and Commerce (SAIC) said on Tuesday that 3,191 food manufacturers had been shut down during the first six months of the year.

    Industrial and commercial departments checked nearly 130,000 fairs and wholesale markets and withdrew 5,757 tons of substandard food from the market, Sun said.

    Lin said the government had paid great attention to recent health scares caused by substandard food products and great efforts were being made to prevent similar incidents.

    In May, China's quality control watchdog confirmed two domestic companies had exported melamine-contaminated wheat gluten and rice protein blamed for the deaths of dogs and cats in the United States.

    Investigations showed the two companies had managed to evade quality checks by labeling products as exports that were not subject to quality inspection.

    However, Lin said the violation was only an "isolated" case and99 percent of China's exported food was up to standard.

    Lin said the government had set up a rigorous quality supervision and inspection system for exported food, which covered all procedures, including planting, processing, distributing and exporting.

    "Starting from planting and breeding to exporting, all procedures are under close supervision," said Lin, deputy general director of the bureau of safety of exported and imported food under the administration.

    Lin said China was open to cooperation and exchanges with other countries on food safety.

    "We are fully confident that Chinese products are not only affordable and fine quality, but also healthy and safe," Lin said.

    The government has come under great pressure to improve food safety following a series of controversies caused by substandard food, ranging from drug-tainted fish to banned Sudan dye used to color egg yolks red.

    A survey showed that about 20 percent of products made in China for domestic consumption failed to meet quality and safety standards in the first half of 2007.

    The survey, conducted by the GAQSIQ, covered 7,200 different products from 6,362 enterprises, with an emphasis on food, daily commodities and farming machinery and fertilizers.

    The administration found that 93.1 percent of products made by large enterprises were up to standard -- the figure was 84.2 percent for medium-sized enterprises and 72.9 percent for small enterprises.

    Wu Jianping, director of the department of production supervision under the GAQSIQ, said China had about 448,000 food manufacturers, 79 percent of which were small factories with fewer than 10 employees.

    "Food produced by small factories and workshops is one of our top concerns, and the small food workshops are the key targets in our food safety campaign," Wu said.

    To improve food safety, the government laid out a five-year plan to tighten the supervision of food and drug products and promised to "significantly reduce the number of incidents caused by substandard food or drug products" by 2010.

    "China will try to reduce the number of small food workshops by half by 2010 so as to effectively curb illegal activities involving shoddy food products," Wu said.

    The quality watchdog dealt with 23,000 cases of fake brand and substandard food from December 2006 to May 2007 and 180 food manufacturers were shut down for making substandard food or using inedible materials in production.