More than 100 foreign-invested companies in Beijing have recently agreed to raise their employees' minimum wages to 1,740 yuan ($266) per month, but workers in retail giants Walmart and Carrefour might not enjoy the benefits, according to the Beijing Municipal Federation of Trade Unions.

This is the first time the Beijing Municipal Federation of Trade Unions of Enterprises with Foreign Investment to release a minimum wage standard for foreign company members, requiring their employees' minimum wages be set at least 1.5 times the city's minimum wage.

Beijing's minimum monthly wage went up from 960 yuan to 1,160 yuan in January this year. This means employees in Beijing-based foreign companies could earn at least 1,740 yuan per month.

The latest standard – based on business performance, affordability and their employees' average wage levels – is set to ensure base-level wages and protect employee interests, the Beijing Times quoted Huang Wei, head of the labor rights department at the Beijing Municipal Federation of Trade Unions, as saying Tuesday.

Employees at multinationals including Nestle (China), Pizza Hut which is under the Yum! Restaurants (China) Investment Co and Siemens China may enjoy the benefits, but those in Walmart (China) Investment Co and Carrefour China might not enjoy the wage increase as the retailers haven't joined in the trade union of enterprises with foreign investment, according to Huang.

"The standard is just a guideline for foreign companies and doesn't have any legal boundary," Zhang Hong, vice president of Aon Hewitt Greater China, a human resource company, told the Global Times Tuesday.

Zhang said the new standard would not affect foreign companies' labor costs much. "The standard applies to companies like Nestle and Siemens, which have higher wage levels than the latest standard," he said. "Companies with lower wage standards didn't join in, so it is more like a show."

Earlier media reports in January show the monthly wages of more than 6,000 workers, including cashiers, tally clerks and security guards, at about 20 Carrefour stores in Shanghai stayed around 1,100 yuan and have barely increased over the past 12 years.

With Shanghai raising its minimum wage to 1,280 yuan this year, Carrefour's senior management reached a deal with the Shanghai Federation of Trade Unions on March 25. Its employees got an 8-percent increase, setting its minimum wage level 5 percent higher than the city's minimum wage.