HONG KONG, May 20 (Reuters) - Shares of Chinese developers were set to open mixed on Monday after China announced "historic" steps to stabilise its crisis-hit property sector.

Hong Kong's Hang Seng Mainland Properties index was set to fall 0.1%, while the Hang Seng Properties Index was set to open up 0.1%.

(Reporting By Hong Kong and Shanghai newsrooms; Editing by Anne Marie Roantree and Tom Hogue)