The share sale, a combination of new and existing shares, will value the maker of medicinal skin care treatments at 19 billion yuan ($3 billion) said the people, who declined to be named as the information was private.

The deal is near closing, but the total investment size may still change, one of the sources said.

The fundraising will likely be followed by an initial public offering in Hong Kong, the sources added.

Giant Biogene and Hillhouse did not immediately respond to Reuters requests for comment.

The Chinese market for so-called "medical aesthetics" products and services is expected to growth 20% in 2021, compared with less than 10% last year, according to a forecast by China Economic Information Service.

Giant Biogene said in a statement on Monday that during China's Singles' Day in November, the world's biggest online shopping event, it had only taken 45 minutes for sales of its key product line called "Kefumei" to exceed the sales logged for the whole day last year.

($1 = 6.3646 Chinese yuan)

(Reporting by Roxanne Liu in Beijing and Kane Wu in Hong Kong; Additional reporting by Scott Murdoch; Editing by Edwina Gibbs)