HONG KONG, May 20 (Reuters) - Shares of most major Chinese developers fell on Monday even after China announced "historic" steps to stabilise its crisis-hit property sector.

Hong Kong's Hang Seng Mainland Properties Index dropped more than 2%, having gained around 18% so far this month after the Politburo said in an April 30 meeting that it would coordinate to clear housing inventory. Embattled state-backed developer China Vanke fell more than 1%, while Sunac China, a major developer which has completed offshore debt restructuring, dropped 2.7%. Shares of China-Ocean slumped more than 3%

China unveiled measures on Friday to facilitate 1 trillion yuan ($138 billion) in extra funding and ease mortgage rules, with local governments set to buy "some" apartments. (Reporting By Hong Kong and Shanghai newsrooms; Editing by Anne Marie Roantree and Shri Navaratnam)