BEIJING — China enacted a labor law Friday meant to improve workers' rights amid complaints about unpaid wages and other abuses, at the same time trying to assure wary foreign investors that they will not be hurt by the new standards.

BEIJING — China enacted a labor law Friday meant to improve workers' rights amid complaints about unpaid wages and other abuses, at the same time trying to assure wary foreign investors that they will not be hurt by the new standards.

The law is the most significant change in Chinese labor law in more than a decade. Its approval followed 18 months of deliberation, public debate and complaints by activists that foreign business groups were trying to erode workers' rights. It takes effect Jan. 1.

The legislation sets standards for labor contracts, use of temporary workers, layoffs and other employment conditions in a rapidly changing economy, according to a report issued by the legislature. The text of the law has not been released.

"The law is meant to protect workers and their rights," Xin Chunying, deputy chairwoman of the legislature's law committee, said at a news conference.

Foreign business groups expressed alarm at an early version of the law that sharply limited use of temporary workers and required approval from China's state-sanctioned unions for layoffs or firing workers. Companies argued that overly restrictive rules would raise the cost of business.

The report Friday made no reference to union approval of layoffs, saying only that a company must inform its union of planned reductions and listen to its opinion.