A senior official yesterday warned against some foreign countries playing up China's product quality issues and using them as trade barriers to protect their domestic trade interests.

"Exaggerating individual cases and doubting the quality of all made-in-China products has hurt our reputation and caused economic losses to our exporters," Qi Xiuqin, director of international cooperation department of the General Administration of Quality Supervision, Inspection and Quarantine (GAQSIQ), said.

She quoted a GAQSIQ report saying more than 30 percent of a sample of 2,500 Chinese exporters suffered economic losses from the imposition of technical trade barriers last year.

The companies lost US$35.9 billion last year, up from US$28.8 billion in 2005, according to a report published yesterday.

Industries particularly affected were the mechanical and electrical sectors, agriculture and food, chemical and mining, plastic and leather.

Guangdong was said to be the most affected province, followed by Zhejiang, Shanghai, Beijing and Fujian, the report said.

Among China's major trade partners, technical trade barriers set up by the European Union, the United States, Japan, Russia and the Association of Southeast Asia Nations have had the biggest influence, it said.

The World Trade Organization (WTO) Agreement on Technical Barriers to Trade (TBT) and the Agreement on the Application of Sanitary and Phytosanitary Measures (SPS) allow members to set regulations and standards for the specific characteristics of a product, such as its size, shape, design, function and performance.

Export products that fail to meet standards in the markets they are destined for will be denied entry to those markets.

In recent years, WTO members have raised technical standards more frequently, which has made it difficult for developing countries to adjust.

China received 875 TBT notifications from WTO members last year, up 13 percent from 2005.

The number of SPS notifications was 1,156, up 36 percent from 2005.

"Not all technical barriers are inappropriate and negative but some are used for trade protection and have had a bad influence on Chinese exporters," GAQSIQ's Yang Song said.

To reduce the impact of technical barriers China will flag inappropriate notifications to WTO members, before adopting other measures such as bilateral negotiations and dispute-resolution mechanisms, Yang said.