Under the terms of the new deal, 2010 US Open champion McDowell will continue to play Cleveland woods, Srixon irons, Cleveland wedges and Srixon balls. He will also wear a Srixon hat and glove and carry a Srixon bag.
"We couldn't be more thrilled that Graeme has decided to remain a member of Srixon's PGA Tour staff," said Todd Harman, President of Cleveland Golf/Srixon.
"Graeme is one of those unique individuals who brings so much to the game of golf. His passion for competition, combined with his love for the game and respect for the fans, has made him the type of ambassador that any company would be honored to have on their staff.
McDowell said: “I couldn't be happier with my current bag and I'm playing some of the best golf of my career."
“The fact that Graeme has chosen to remain in the Srixon family says an awful lot in regards to how he feels about our products, as well as our company."
McDowell himself added: “I'm thrilled to remain a member of the Srixon and Cleveland Golf family.
“I couldn't be happier with my current bag and I'm playing some of the best golf of my career. Much of that has to do with their exceptional equipment, coupled with the tremendous support they've continually given me. I'm now looking to taking things forward again and accomplishing many of my professional goals over the coming years."
In the short-term, McDowell has a much more pressing personal goal to accomplish – he marries fiancée Kristen Stape in the Bahamas tomorrow.