By Andy Silvester 888, the gambling giant which owns William Hill and a host of other major brands, looks set to exit the US market despite the country’s sports-betting boom – giving up its operation of US site SI Sportsbook. Gambling analysts have pegged the US as a newgold rush for gambling giants as individual states gradually legalise sports betting and the major sports leagues have jumped in bed with players including DraftKings and FanDuel. However 888 is to conduct a ‘strategic review’ of its US business and also bring to an end its partnership with Authentic Brands Group, which had see…