Samsung Electronics Chairman Jay Y. Lee was found not guilty of accounting fraud and stock manipulation by a Seoul appeals court on Monday, in a ruling that could remove long-running legal risks that he has faced from criminal cases.

Samsung Electronics Co. Executive Chairman Jay Y. Lee successfully defended against an appeal by prosecutors, a step forward for South Korea’s largest company that has remained under a years-long cloud of financial impropriety charges.

A Seoul appeals court on Monday upheld the acquittal of Samsung Electronics Executive Chairman Jay Y. Lee in accounting fraud and stock manipulation in a