A spokesman for the China Securities Regulatory Commission said investors will be allowed to sue Everbright over possible losses, according to state television, the newspaper China Securities Journal and other outlets. There has been no word on the size of potential losses.
Former CEO Xu Haoming, who resigned last week, was banned for life from the securities industry.
Similar bans were imposed on the general manager of the firm's finance department, an assistant to Xu and the head of computerized trading. The four also were fined 600,000 yuan ($97,000) each.
The four were accused of insider trading, providing misleading information and violation of management rules, the reports said. They gave no grounds for the insider trading charge.
Everbright, China's fifth-largest brokerage, also was ordered to stop trading for its own account and applications to launch new business lines will be suspended, the news reports said.
The incorrect orders caused trading volume on Aug. 16 to spike to more than 50 percent above the previous day's level.
Everbright's orders totaled 23.4 billion yuan ($3.7 billion), according to the CSRC. It said completed transactions were almost 7.3 billion yuan ($1.2 billion).
The brokerage asked to cancel the trades, the government-run China News Service reported earlier. However, the Shanghai Stock Exchange said any transactions that already had been completed would be cleared normally.
Everbright is part of the state-owned China Everbright Group, which also controls banks and other financial businesses. Everbright Securities raised $1.6 billion in a 2009 by selling a portion of its equity to private investors.