* HSI -1.1 pct, H-shares -1.2 pct, CSI300 +0.3 pct
* Rebound in China property on private placement approval
* China railway stocks rise on construction plans
(Updates to midday)
HONG KONG/SHANGHAI, March 20 (Reuters) - Hong Kong shares, tracking overseas weakness, fell on Thursday on news the Federal Reserve might raise U.S interest rates sooner than previously thought.
China stocks rose slightly, thanks to a rebound in property counters after two Chinese developers said they received a green light for private placements, and railway counters climbed on construction-project approvals.
At midday, the Hang Seng Index was down 1.1 percent at 21,324.96 points. The China Enterprises Index of the top Chinese listings in Hong Kong fell 1.2 percent.
The CSI300 rose 0.3 percent, while the Shanghai Composite Index was up 0.4 percent at 2,028.85 points. Both swung between negative and positive territory in the morning trade.
Federal Reserve Chair Janet Yellen said the central bank might end its bond-buying programme this autumn and could start to raise interest rates six months after that.
Her comment hit all Asia-Pacific stock markets, as analysts previously have assumed U.S. interest rates won't rise until late 2015.
Ben Kwong, chief operating officer of stockbroker KGI Asia, said Hong Kong reacted negatively to the Fed statement because its stock market is sensitive to interest-rate changes.
He also said a lack of positive news on the Chinese economy meant investor interest was focused on individual stocks such as software companies and firms linked to Chinese Internet giant Alibaba.
Shares in one of the two Chinese developers that received private placement approval, Tianjin Tianbao Infrastructure Co. , rose 2.8 percent. The second firm, Join In Holding , fell 0.4 percent.
Chinese railway counters rose after Beijing approved five railway construction projects worth 142.2 billion yuan ($22.95 billion). The China Securities Journal quoted analysts as saying the announcement was made as a sign of stability for the market.
In Shanghai, Guangshen Railway jumped 5.5 percent and Daqin Railway rose 2.4 percent.
Warren Buffett-backed Chinese automaker BYD Co fell 8.8 percent in Hong Kong and 3.6 percent in Shenzhen after the company reported 2013 net profit up 580 percent at 553.1 million yuan ($89.26 million). 1/8ID: nL3N0MG2N0 3/8
Shares in Hong Kong-listed China Mobile slipped 1.9 percent ahead of its 2013 earnings due later on Thursday. ($1 = 6.1965 Chinese Yuan)
(Editing by Richard Borsuk)