Weening won Stage 5 of this year's Giro d'Italia, triumphing by eight seconds after 23km of strade bianche. He then went on to wear the pink jersey for four days. He rose to prominence in 2005 with his first Grand Tour stage victory at the Tour de France, besting Andreas Klöden on Stage 8.
"But it's now time for the next stage in my career and joining GreenEdge is a great new opportunity for me to help build a team and pursue my own ambitions.
"I'm also looking forward to being part of a team from Australia, which is one of the most exciting cycling countries in the world. They can't be producing so many promising young cyclists without doing something right."
"Being able to win at the two biggest tours in the world doesn't come by chance, particularly when you look at the quality of the victories across such difficult terrain," he said.
"Pieter brings great climbing qualities for our grand tour ambitions and also has plenty to offer in the one day classic, where we'll be aiming to make a mark.
"A key factor in going after Pieter and getting him to sign with the team is he's at a great point in his career. He's been in the professional peloton for eight seasons yet is only 30 years of age. This is the perfect balance of experience while still being his prime."
Today's announcement follows the recruitment of Stuart O'Grady, Jack Bobridge, Cameron and Travis Meyer along with Daniel Teklehaymanot.