BEIJING - It was not human error, but design flaws in a trade unit of China Everbright Securities (CES) that triggered the anomalous trades on Friday, according to the China Securities Regulatory Commission (CSRC) on Sunday.

The Everbright proprietary "strategy trading system" has flaws in aspects like program call and limit control and the flaws were triggered sequentially, resulting in huge orders at market prices, said a CSRC spokesperson.

The total declaration for buying totalled 23.4 billion yuan ($3.8 billion) and the actual transactions topped 7.27 billion yuan, the spokesperson said.

CES also acknowledged the flaws in the strategy trading system at a press conference on Sunday evening.

CES suffered an overall loss of 196 million yuan on Friday trading, according to the conference.

CES is actively collaborating with the regulating authorities in the investigation, said Xu Haoming, the CES president.

The company has sealed up the system and trading data as well as documents and transaction flow. A scrutiny on all the trading systems is under way, said Xu.

CES will perform its duties and obligations on investor compensation according to law, said Mei Jian, secretary of the CES board of directors.

The erroneous trade caused a swift rise in domestic A-share stocks in minutes at the end of Friday morning trade. The benchmark Shanghai Composite Index spiked 5.96 percent within three minutes on Friday.