HONG KONG, March 5 (Reuters) - Fosun International is looking to sell all or part of its luxury resort Atlantis in southern China as part of its efforts to reduce debt, three people with knowledge of the matter said.

Located on Hainan island, known as China's Hawaii, in the seaside city of Sanya, the integrated resort spans an area equivalent to 66 soccer pitches. It boasts a hotel with more than 1,300 guest rooms - some with views of underwater marine life - as well as a water park, an aquarium and a shopping mall.

Fosun, known for once being one of China's most acquisition-hungry conglomerates, has sent information to prospective buyers and advisers and has been in informal discussions with them in recent months, said two of the people.

A potential deal value for Atlantis Sanya could not be immediately learned. Fosun said in 2018 it had invested 11 billion yuan ($1.5 billion) in the resort.

The sources declined to be identified as the discussions were confidential. Fosun and its Hong Kong-listed unit Fosun Tourism Group, which owns the resort, did not immediately respond to requests for comment.

A sale would be further evidence that the conglomerate, which had some $30 billion in debt as of last June, is willing to roll back its presence in the tourism sector. Fosun Tourism's other main asset is Club Med and sources have said that the conglomerate is exploring the sale of a minority stake in the luxury resort chain.

According to two of the sources, Fosun has targeted mainly Chinese state-backed firms and deep-pocketed investors from the Middle East as potential buyers.

It is open to selling the whole business or the luxury hotel alone, said one of them.

Fosun Tourism, which has a market cap of about HK$5.2 billion ($665 million), accounts for 9% of Fosun International's overall revenue. The conglomerate's other businesses span healthcare, financial services and property. ($1 = 7.1993 Chinese yuan) ($1 = 7.8252 Hong Kong dollars) (Reporting by Julie Zhu and Kane Wu; Editing by Edwina Gibbs)