For deceptive pricing practices and refusing to hike wages for more than a decade, French retailer Carrefour has come under criticism in China but is taking measures to soothe public anger.

According to media reports, the salaries of more than 6,000 employees at about 20 Carrefour stores in Shanghai barely changed between 1998 and 2010 while the average salary of Shanghai workers more than tripled during the period.

In addition, the retailing giant has refused to hike wages, declining to accept the collective wage negotiation mechanism that has been practised in China since the 1990s.

Sources with the Shanghai Municipal Federation of Trade Unions said Carrefour officials and representatives of the company's trade union discussed issues again Thursday.

The results of the closed-door negotiations are not likely to be revealed anytime soon, and observers remain suspicious about the talks.

"China does not have a compulsory punishment system for those businesses that reject the collective wage negotiation mechanism," said Xia Yongmei, executive vice chairwoman of the trade union in Shanghai's Xinzhuang industrial zone.

The French retailer is involved in another scandal, too - 11 of its China stores were caught overcharging customers for products including cotton underwear and tea.

The stores must pay a fine five times the amount they overcharged, or 500,000 yuan (75,757.5 U.S. dollars) if they can't calculate that amount, according to the National Development and Reform Commission.

The company has apologized and offered to refund customers five times the difference between the price charged and the one on the label.