Hong Kong shares falter before U.S.-China trade deal

* Hang Seng falls 0.4%, H-shares down 0.5%

* U.S. to keep tariffs on China until Phase 2 deal - Mnuchin

* Analysts question China's pledge to ramp up U.S. purchases

HONG KONG, Jan 15 (Reuters) - Stocks in Hong Kong edged down on Wednesday after the United States warned that tariffs on Chinese goods will remain in place, hours before the two sides prepared to seal a Phase 1 trade deal.

** At the close of trade, the Hang Seng index was down 0.4% at 28,773.59. The Hang Seng China Enterprises index fell 0.5%.

** The sub-index of the Hang Seng tracking energy shares dipped 1.3%, the IT sector rose 0.1%, the financial sector fell 0.3% and the property sector lost 0.2%.

** The top gainer on the Hang Seng was AAC Technologies Holdings Inc, which rose 1.2%, while the biggest loser was CNOOC Ltd, which fell 2.4%.

** The lacklustre session took Hong Kong shares further away from the eight-month high hit on Tuesday after the U.S. Treasury withdrew its designation of China as a currency manipulator - a major de-escalation of the 18-month trade conflict.

** Trump is set to sign the Phase 1 trade deal with Chinese Vice Premier Liu He at the White House on Wednesday at 11:30 a.m local time. (1630 GMT).

** But U.S. Treasury Secretary Steven Mnuchin said on Tuesday that the United States will maintain tariffs on Chinese goods until the completion of a second phase of a U.S.-China trade agreement.

** China has pledged to buy almost $80 billion of additional manufactured goods from the United States over the next two years as part of the trade truce, according to a source, though some U.S. trade experts call it an unrealistic target.

** In Hong Kong, local jewellery chain operator Chow Tai Fook Jewellery dropped as much as 2.4% after it announced plans to trim its domestic store network, which involved many shops in tourist districts.

** About 1.24 billion Hang Seng index shares were traded. The volume traded in the previous trading session was 1.64 billion.

** At close, China's A-shares were trading at a premium of 26.81% over Hong Kong-listed H-shares. (Reporting by Noah Sin; Editing by Shailesh Kuber)