China Pharmaceutical Group said it would buy pharmaceutical assets from its parent company for HK$8.98 billion ($1.16 billion) as it aims to expand its finished drug business and curb reliance on intermediates and bulk drugs.

Chinese pharmaceutical firms are facing increasing challenges as Beijing introduces price controls as part of healthcare reforms to offer affordable medical services to the country's 1.3 billion people.

In a filing to the Hong Kong bourse late on Tuesday, the Hong Kong-listed firm said it would buy pharmaceutical products maker and distributor, Robust Sun Holdings, from Joyful Horizon, an indirect unit of its ultimate parent Hony Capital Fund III.

The assets to be acquired include a researcher and manufacturer of drugs for use in diseases relating to central nervous system.

Shares of the company have risen nearly 20% so far this year, outpacing an almost three percent rise in the benchmark Hang Seng Index.