The 27-year-old made 51 first-class appearances for Leicestershire after arriving at Grace Road in 2009, but informed the club at the end of last season that he wanted to move on.
Chief executive Mike Siddall said: "Having entered into discussions with Wayne at the end of the season he advised us that he no longer wished to play for the club."
He added: "The board agreed that it would be in the best interest of club and player that he leaves and a deal has been agreed for his immediate move to Old Trafford."
Head coach Phil Whitticase said: "While we are disappointed to lose Wayne we only want players at Grace Road who have a real desire to play for the club.
"We have sufficient quality in the squad to make up for Wayne's departure, with an excellent group of committed players."
- Sports & Recreation