Chinese mainland stocks fell for the first time in three days, led by commodity producers, amid speculation raw-material prices will extend declines as a faltering economic rebound curbs demand.

The Shanghai Composite Index had slid 0.8 percent at the close. Jiangxi Copper Co and Angang Steel Co dropped at least 1.2 percent, while Yanzhou Coal Mining Co retreated the most in two weeks. The Hang Seng China Enterprises Index was little changed. Turnover slumped in Shanghai and Hong Kong.

Raw materials have been on a tumultuous ride this year after tentative signs of a demand revival in China ignited a firestorm of speculation. The frenzy led to a clampdown from regulators and exchanges, weakening prices once more, including for iron ore and steel.

Chinese manufacturing gauges and trade figures have also missed predictions, while a high-profile warning by the People's Daily about elevated levels of debt have damped hopes for more easing.

"Game is over for speculation on ferrous metals," said Steve Wang, chief China economist at Reorient Financial Markets Ltd in Hong Kong. "The official stance is clearly against speculation as State media and regulators seek to stabilize prices. Ferrous metals prices have made a round trip back to where their rally started in February and March."

The Shanghai Composite closed at 2,821.67 points. The Hang Seng Index added 0.1 percent as turnover fell 20 percent.

Gauges of materials and telecom companies in the CSI 300 slid at least 1 percent for the steepest losses among 10 industry groups. Angang Steel Co declined 2.1 percent, while Yanzhou Coal Mining plunged 3.1 percent.

Ore with 62 percent content sank 6.7 percent to $51.22 a dry metric ton on Monday, the lowest level since March 3, according to Metal Bulletin Ltd. After romping 23 percent higher last month as China's ill-fated frenzy gathered pace, the price has tumbled by the same amount so far in May.