China's securities regulator investigated 140 new insider trading cases in the first six months of this year, accounting for 46 percent of all new cases.

In the first half, the China Securities Regulatory Commission (CSRC) expanded the scope of law enforcement and prioritized interconnected cases of insider trading, spokeswoman Gao Li said at a press conference.

CSRC launched preliminary investigations into 104 insider trading cases and filed formal investigations into 36 such cases in the first half.

There were nine insider trading cases with transaction value of more than 10 million yuan (1.47 million U.S. dollars) each, Gao said, adding that the highest transaction reached 270 million yuan.

In total, the commission investigated into 302 new cases of different violations. Cases related to information disclosure and market manipulation continued to rise, Gao said.