The growing wave of Chinese companies looking to delist from US stock markets is rattling insurers that have sold them millions of dollars worth of cover for defence costs in the event of shareholder lawsuits.

Insurers in Asia and Europe that are exposed through directors’ and officers’ liability policies are looking at ways to exclude this cover, according to lawyers at RPC, the London-based firm, though brokers say it would be extremely tough for them to strip it out of existing policies.

At least 16 companies with a value of about $4bn have completed deals to take themselves private – often with private equity backing – as their share prices have performed poorly and the entrepreneurs and executives behind them have struggled to engage US investors and analysts.