A Shanghai-based unit of Citadel Securities LLC has paid 670 million yuan to settle a trading irregularity case in China, The Wall Street Journal reported, citing the China Securities Regulatory Commission.

The settlement ends the regulator's probe into Citadel Shanghai Trading Ltd. over allegations that it broke account and asset management rules during the 2015 market rout in China. The "administrative reconciliation" took place at the end of 2019, and Citadel did not admit to any wrongdoing.

The company's proprietary trading account was frozen during the investigation. Citadel now hopes to expand in China, a spokesman told the Journal.

As of Jan. 17, US$1 was equivalent to 6.86 Chinese yuan.