Pettybourne will commit to a two-year deal with the powerful English club at the end of this season.
“It’s an opportunity just too good to pass up,” Pettybourne said.
“It’s something that’s always interested me and I’m looking forward to the challenge. I just reckon the time is right for me.
“I will leave Wests Tigers on good terms and appreciate the fact they have allowed me to challenge myself overseas.”
Wests Tigers Coach Mick Potter wished Eddie all the best with his new challenge.
“We haven’t had the chance to see the best of Eddie due to injuries but I am sure he will be a great asset to Wigan,’’ Potter said.