As one door closes, another door shuts. Hundreds of Chinese companies trading in the US face delisting in the next few years. Congress passed legislation to force groups to comply with US accounting rules this month. But a secondary listing in mainland China may not be the back-up CEOs had hoped for.

The Shanghai and Shenzhen stock exchanges are tightening regulations. Proposed revisions will make delisting of listed companies much easier. Businesses whose market values fall below a fixed threshold of about $46m for 20 trading days will be in the line of fire.

Delistings have been relatively rare in China. Just over 120 companies have quit Chinese bourses in the past decade, despite a slew of initial public offerings. As a result, there are more than 4,100 listed companies in China, similar to the number in the US, where delistings average upwards of 200 a year.