The Hong Kong bourse had issued a notice of the suspension before the market opened but gave no details.
The Beijing-based company said the shares were suspended pending an announcement regarding an issue of convertible bonds and placing of existing shares and top-up subscription of shares under a general mandate. It gave no further details.
Xiaomi has raised $3.91 billion as part of a deal that includes Hong Kong's largest top-up placement and a convertible bond deal, according to a term sheet seen by Reuters.
(Reporting by Donny Kwok; Editing by Christopher Cushing and Raju Gopalakrishnan)