SHANGHAI, Jan 25 (Reuters) - China shares ended at a 15-month low on Tuesday, dragged lower by weakened sentiment over concerns that the U.S. Federal Reserve would tighten policies and uncertainties in the markets ahead of the incoming Chinese New Year holidays.

** The blue-chip CSI300 index fell 2.3% to close at 4,678.45, its lowest since October 2020, while the Shanghai Composite Index lost 2.6% to 3,433.06.

** The CSI Smallcap 500 Index and the start-up market ChiNext both declined 3.4%.

** Nearly 94% of the stocks listed in China's A-share markets dropped, according to data from financial information services provider Wind.

** Refinitiv data showed outflows of more than 148 million yuan through the Northbound legs of the Stock Connect programme ,, showing overseas investors were net sellers of A-shares.

** Real estate developers lost 3.3% on concerns over debt woes in the squeezed sector.

** Energy stocks slumped 3.8%, with coal miners down 4.7%.

** Consumer staples and semiconductors lost roughly 2.3% each, while new energy stocks closed down 2.5%.

** Media firms plunged more than 6%, after the Cyberspace Administration of China (CAC) launched a month-long "clean cyberspace" campaign.

** The Fed will begin its two-day meeting later on Tuesday, and Chinese markets will be closed for the New Year holidays starting from Jan. 31.

** Geopolitical uncertainties in Europe also weighed on sentiment, with NATO saying on Monday that it was putting forces on standby and reinforcing eastern Europe with more ships and fighter jets, in what Russia denounced as Western "hysteria" in response to its build-up of troops on the Ukraine border.

(Reporting by Shanghai Newsroom)