washington u.s. supreme court tuesday reject challenge procter gamble co company way california impose tax businesses operate multiple state justices leave place december 2015 rule california supreme court california bind 1967 agreement state set formula calculate tax california join multistate tax compact 1974 change formula 1993. california since withdraw state compact several company include two procter gamble subsidiaries kimberly-clark worldwide inc merck kgaa subsidiary sigma-aldrich corp sue 2010 deny refund tax pay 1993 2005. company say overpay tax 34 million lawyers company say 750 million potential tax refund california additional amount state stake case many state move away multistate tax compact formula favor attract businesses within border state rearrange way tax business income in-state businesses pay less out-of-state businesses pay u.s. supreme court turn away company california tax dispute