Hanoi  - Eight hundred workers at a joint-venture garment factory in the northern port city of Haiphong have launched a wildcat strike, Vietnamese officials said Monday.

Workers at the Singaporean-owned Sin Joo Boo garment company went on strike Sunday after a new managing director reduced the per-garment payment scale, said Nguyen Duc Van, chairman of the government-affiliated trade union in Haiphong's Duong Kinh district.

Van said the old scale of per-garment payments, which workers receive in addition to their fixed salaries, had been in place for many years. The new managing director lowered the payments in October after arriving from Singapore to take up his job, but did not inform workers until the salaries were paid at the end of the month.

"We have asked the company to restore the old salary scale for October, and to publicly inform workers about the new scale starting in November," said Van. "If the workers find it acceptable, they can continue work, and if not, they can leave the company."

Van said some workers had also complained about the quality of their company-provided meals and said the company had forced them to work longer shifts without pay, but he said these claims were not true.

Calls to the Sin Joo Boo company were not returned.

Sin Joo Boo has about 900 workers at its facility in Haiphong. Garment workers in Vietnam are paid between 80 and 120 dollars per month.

In Vietnam, strikes are typically launched independently by informal groups of workers. Local government and union officials like Van then negotiate between workers and management.

Union officials are not exclusively loyal to workers' interests, but take government and company interests into account.

The latest available figures from Vietnam's national trade union showed there were 46 wildcat strikes in the first three months of 2009, compared with 113 cases in the same period last year.

Strikes rose in 2008 due to high inflation. In 2009, they have slowed, in part due to worker anxiety over job security. (dpa)