China Stocks Extend Strong Falls

China’s Shanghai Composite Index tumbled to its lowest level since March 20 as rallies by state-owned giants failed to outweigh a record drop in margin bets.

The benchmark stock gauge sank 3.9 percent to 3,626.96 at 11:10 a.m. local time, with more than 50 stocks falling for every one that rose. Material producers, technology and health-care shares led losses, while PetroChina Co. surged 7.3 percent on speculation of state fund buying. Traders cut 93.6 billion yuan ($15 billion) worth of holdings of shares purchased with borrowed money on the Shanghai exchange on Monday, the most since at least 2010.

A flurry of measures to stabilize the market, including a pledge by state-run financial firms to buy 120 billion yuan worth of shares and a halt to initial public offerings, is failing to stop the rout that erased more than $3.2 trillion of value in less than a month.