BEIJING - As China's labor dispute cases tripled from 407,000 in 2005 to 1.287 million last year, the country needs more arbitration centers to protect employees' legitimate rights and sustain steady and rapid economic growth, a senior official said Wednesday.

"Labor disputes cases rocketed to more than a million in 2008 and remained so ever since," ?said Li Xiaohu, vice-director of labor dispute arbitration branch of the Ministry of Human Resources and Social Security (MOHRSS).

Labor arbitration became a free service across the country in 2008 when the labor dispute intermediation law went into effect.

"The soaring cases show that enterprises and workers are getting used to solving problems in a legal way," said Zhou Tianyong, a professor of social insurance at the Party School of the Central Committee of the Communist Party of China (CPC).

"It indicates that labor arbitration has become the main channel to solve labor disputes, instead of extreme ways such as blocking roads and attempted suicides," Zhou said.

Labor disputes involving more than one worker are increasing. According to MOHRSS, some 9,000 such cases, involving 212,000 workers, were handled in court in 2010.

Officials welcome this change.

"Massive protests over labor disputes are rare in areas where the arbitration system works well," said Liu Jianxin, deputy magistrate of the county of Yudu in eastern Jiangxi province.

"Not a single worker has petitioned to the county government over labor disputes in our county," Liu said. "This is a good sign that workers are willing to solve disputes through labor arbitration."

Along with the soaring cases, the demands for more courts of arbitrations rose too, following the implementation of new laws and regulations on social security, Zhou said.

Previously, workers turned to arbitration over salary disputes, now it's more about pensions, health insurance and other social welfare.

China had only 946 arbitration centers at the end of 2010, compared with more than 3,200 administrative organizations above the county level, according to MOHRSS. In cities like Shenzhen, an arbitrator has to solve 150 cases each year on average.

"We just need more arbitrators," Li said.