After trading in China was halted automatically the second time this week, officials said Thursday that they’re suspending the “circuit breaker” that shuts down the market if a key index falls by 7 percent.

China’s securities regulator has said the launch of the registration-based IPO system will not occur on March 1 as previously reported. On Thursday, the 7 percent threshold was reached, halting all trading, less than half an hour in the entire trading day.

Under the circuit breaker system, markets were suspended for 15 minutes if the CSI 300 index of Shanghai and Shenzen stocks fell by five per cent.

While some analysts criticized the design of the circuit breaker, saying it inadvertently encouraged bearish sentiment, the CSRC said the mechanism had helped calm markets and protect investors – although it said the mechanism needs to be further improved.

London’s benchmark FTSE 100 index rose 0.4 percent to 5,977.6 points compared with Thursday’s close.

Big shareholders, the management and those who hold more than 5 percent of a company’s shares were asked not to sell more than 1 percent of the company’s shares within any three-month period, a notice said. The impact is that well over 75 percent of shareholders were banned from selling.