Pettybourne will commit to a two-year deal with the powerful English club at the end of this season.
Its an opportunity just too good to pass up, Pettybourne said.
Its something thats always interested me and Im 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.
Pettybourne joined Wests Tigers this season after six years with the South Sydney Rabbitohs.
Wests Tigers Coach Mick Potter wished Eddie all the best with his new challenge.
We havent 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.