Williams has a remarkable record in his first-class career, with 123 wickets at 23.15 bowling right-arm medium fast, and has also taken 81 wickets across the white-ball formats.
“The lads have made me feel at home here already and I am now looking forward to playing at Emirates Old Trafford for the first time in front of our members and supporters and helping this great club to challenge for trophies again.”
Chilton said that Williams had been identified as a potential overseas player last winter before the club had learned that he held a British passport and was “considering the option” of moving to the UK to play as a local player.
“Due to injuries and international selection, we required a seamer at short notice for last month’s County Championship matches,” Chilton said. “Following Will’s performances in those matches, and through conversations with him since, we have taken the decision to turn his short-term overseas contract into a local player contract.
“This is an exciting opportunity for us, and for Will, and he has already been a really nice fit into the club in terms of the type of cricketer he is and we look forward to him developing with us over the course of the next three-and-a-half seasons.”
Source: ESPN Crickinfo