HONG KONG, Sept 10 (Reuters) - The Hong Kong unit of ratings agency Moody's Corp breached the regulator's code of conduct in the publication of a 2011 report on Chinese companies, a Hong Kong appeals tribunal heard on Thursday.

The allegations were heard during Moody's Investors Services HK Ltd's appeal against a decision by Hong Kong's markets watchdog to fine the company $3 million for a July 2011 report that raised concerns about corporate governance at 49 Chinese Hong Kong-listed companies.

Moody's said the regulator overstepped its mark in claiming the report was akin to a credit rating, which would fall under the regulator's code of conduct.

(Reporting by Michelle Price; Editing by Stephen Coates)