Most of the companies involved are small-cap names, however, they also included some larger firms including embattled bad debt manager China Huarong Asset Management and solar energy firm GCL-Poly Energy.

Many of the filings said the companies had not published their 2020 full-year results by the end of March, some citing difficulties caused by the COVID-19 pandemic. Hence, shares of these companies had to be suspended from trading under Hong Kong's listing rules.

Last year, 384 Hong Kong companies did not publish annual results by March 31, but were able to continue trading after publishing unaudited accounts or other financial information after the stock exchange and markets regulator relaxed the rules due to the pandemic.

Such arrangements were not permitted this year.

The financial reporting year of many of the approximately 2,500 Hong Kong-listed companies is the same as the calendar year.

(Reporting by Alun John and Donny Kwok; Editing by Kim Coghill and Sherry Jacob-Phillips)