* Hang Seng index ends down 2.3 pct
* China Enterprises index HSCE falls 1.7 percent
* HSI financial sector sub-index is 2.3 percent lower; property sector down 2.1 percent
March 5 (Reuters) - Hong Kong stocks fell the most in three weeks on Monday as the prospects of a global trade war continued to haunt investors.
** US President Donald Trump said last week he would impose significant tariffs on steel and aluminium imports. UBS Securities wrote on Monday "it is possible that Trump may impose tariff on a wide range of Chinese exports."
** The Hang Seng index fell 2.3 percent to 29,886.39, while the China Enterprises Index lost 1.7 percent to 11,991.79.
** The sub-index of the Hang Seng tracking energy shares dipped 1.8 percent while the IT sector dipped 2.37 percent, the financial sector was 2.31 percent lower and property sector dipped 2.08 percent .
** The top gainer on Hang Seng was Sunny Optical Technology Group Co Ltd, up 0.93 percent. The biggest loser was China Unicom Hong Kong Ltd, which fell 5.93 percent.
** China's main Shanghai Composite index closed up 0.09 percent at 3,254.5283 while its blue-chip CSI300 index ended up 0.05 percent.
** Around the region, MSCI's Asia ex-Japan stock index was weaker by 1.2 percent while Japan's Nikkei index closed down 0.66 percent.
** The yuan was quoted at 6.3408 per U.S. dollar at 08:21 GMT, 0.05 percent weaker than the previous close of 6.3379.
** As of the previous trading session, the Hang Seng index was up 2.22 percent this year, while China's H-share index was up 4.2 percent. As of the previous close, the Hang Seng has declined 0.85 percent this month.
** The top gainers among H-shares were Sinopharm Group Co Ltd up 0.86 percent, followed by BYD Co Ltd gaining 0.71 percent and China Minsheng Banking Corp Ltd up by 0.38 percent.
** The three biggest H-shares percentage decliners were China Gas Holdings Ltd which was down 4.33 percent, New China Life Insurance Co Ltd which fell 3.4 percent and ZhongAn Online P & C Insurance Co Ltd down by 3.3 percent.
** About 2.35 billion Hang Seng index shares were traded, roughly 80.2 percent of the market's 30-day moving average of 2.93 billion shares a day. The volume traded in the previous trading session was 3.05 billion.
** At close, China's A-shares were trading at a premium of 30.28 percent over the Hong Kong-listed H-shares. (Reporting by the Shanghai Newsroom; Editing by Gopakumar Warrier)