SHANGHAI, Dec 24 (Reuters) - China’s blue-chip stock index and Hong Kong shares inched higher on Thursday morning as progress in Brexit talks lifted sentiment globally, although Jack Ma’s Alibaba Group tumbled after Beijing launched an anti-monopoly probe. ** China’s benchmark CSI300 index rose 0.1% to 5,013.48 by the end of the morning session, though the Shanghai Composite Index lost 0.2% to 3,375.21. ** In Hong Kong, the Hang Seng index added 0.2% to 26,386.56. The Hong Kong China Enterprises Index lost 0.5% to 10,430.53. ** Investors cheered news that Britain and the European Union were on the cusp of striking a narrow trade deal on Thursday, which would help avoid shipping and travel chaos on both sides of the English Channel. ** Index heavyweight Alibaba tumbled as much as 8.9% in Hong Kong to the lowest level since July 6, after China launched an antitrust investigation into the e-commerce and fintech empire. ** The probe is part of an accelerating crackdown on monopolistic behaviour in China’s booming internet space, and the latest setback for Alibaba founder Jack Ma. ** Spooked investors also dumped shares of Alibaba’s affiliates, as well as other internet firms that risk being targeted by Chinese anti-trust regulators. ** Alibaba Health Information Technology slumped 11.1%, while Shanghai-listed Hundsun Technologies Inc , also an Alibaba affiliate, dropped over 4%. Ali Pictures lost 2.1%. ** Internet giants Meituan and JD.com also fell, both losing over 2%. The Hang Seng tech index dropped 3.2%. (Reporting by Samuel Shen and Andrew Galbraith; Editing by Subhranshu Sahu)