** Mobvista 1860.HK plunges 38.1% to HK$5.68; set for biggest ever one-day pct decline

** Stock hits lowest since November 24, 2024; second-biggest pct loser on Hong Kong bourse

** Chinese game publishing and mobile ad services provider says two U.S. laws introduced in 2024 and the new America First Investment Policy may affect its Mintegral and marketing tech businesses

** Adds it is still in process of evaluating potential disposal of the two businesses

** Co has not entered into binding agreement with any potential buyers

** Mobvista earns significant rev from U.S.

** Stock down 24.7% YTD

($1 = HK$7.7755)

(Reporting by Donny Kwok)

((donny.kwok@thomsonreuters.com))