BEIJING--A major footwear maker in southern China on Thursday offered to make disputed social-insurance payments to settle a four-day strike that had disrupted production at the key supplier for some of the world's best known shoe brands.

Executives at Yue Yuen Industrial (Holdings) didn't say how much the payments would cost, though an independent labor group said they could total 100 million-200 million yuan ($16 million-$32 million) if they involve many years of back payments.

"The basic principle is that today we've promised our employees to make a delayed payment to social insurance and the housing fund," George Liu, executive director of Yue Yuen Industrial, told The Wall Street Journal. "The move will affect a large number of employees, so we'll have to work with local government agencies to work out the details, and that takes time."

Some of the employees at Yue Yuen Industrial in Dongguan, Guangdong province, walked off the job on Monday in a dispute centered on levels of social-insurance coverage.

It was unclear how many workers joined the strike, but Hong Kong-listed Yue Yuen employs more than 40,000 workers at its Dongguan facilities and is a supplier for Adidas AG and Nike Inc.

Workers said the company has been making social insurance contributions based on basic wages rather than total pay as required by law.

At least one employee was skeptical about the latest offer from the company. The worker, who gave his surname as Li and said he was 38 years old, said his monthly salary is about 3,500 yuan, but payments to his social insurance were based on income of 1,810 yuan.

Yue Yuen's Mr. Liu said he couldn't estimate of how much would be paid out because workers would have to top up their own contributions to the social insurance fund and may choose not to make those payments.

The worker Mr. Li, who has been employed at the company for 18 years, said he and others would be unable to pay their share of the social insurance contribution under the latest plan. "Our salary is low, and we have to support our family. How do they expect us to take tens of thousands of yuan out of our pocket?"

Yue Yuen's payments could be more than 100 million-200 million yuan since it owes contributions to a social insurance, as well as a housing fund, for more than a decade, said Zhang Zhiru, director of the not-for-profit Shenzhen Spring Breeze Labour Disputes Service Centre.

The walkout at Yue Yuen is the first large-scale strike in which workers asked for better social security benefits, the labor-right activist said. In the past China's workers pushed hard for higher wages and overtime compensation, but as larger numbers of laborers approach retirement age they have begun to place greater importance on having a social safety net, Mr. Zhang said.

The average age of the workers in China in 2012 was 37.3 years old. Workers age 16 to 30 accounted for 36.8% of the total in 2012, down from 39% in 2011, the National Bureau of Statistics said in an annual survey released in May last year.

The Dongguan Social Security Department couldn't be reached for comment, and an official of the Dongguan Federation of Trade Union said it didn't have any immediate comment.

Mr. Liu, the Yue Yuen executive, said that not all of the company's production had been affected by the dispute but that there had been significant disruption. "We will do this (make the back payments) according to all government regulations," he said. "We hope and need the employees to go back to work."

--Liyan Qi

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