** Hong Kong-listed shares of Alibaba 9988.HK rise 4.4% to HK$172, their highest level since October 30

** Stock set for its best day since January 14, and a third consecutive session of gains, if current trend holds

** Stock is second-biggest pct gainer in Hang Seng Tech Index .HSTECH, which climbs 0.8%

** Co's U.S.-listed stock BABA.N rose 5% on Thursday, its best day since January 12

** Alibaba is preparing to list its chip-making arm, T-Head, Bloomberg News reported on Thursday, citing people familiar with the matter

** The process is still at an early stage and the potential valuation of the unit remains unclear, according to the report

** Reuters could not immediately verify the report. Alibaba did not immediately respond to a request for comment

** YTD, Hong Kong stock up 19.6%, while U.S. shares up 20.9%

(Reporting by Donny Kwok)

((donny.kwok@thomsonreuters.com))