World number three golfer Phil Mickelson is the latest top pro to get into the signature design business.

Mickelson, whose first foray into the business came at Whisper Rock Golf Club in Arizona in 2001, which he designed along with golf architect Gary Stephenson, has now opened his own design firm in partnership with Stephenson. Phil Mickelson Design, in low-key operation since August 2006, has already signed contracts, conducted site visits and begun extensive design plans for two private course projects, and is in negotiations with two other properties.

"I thoroughly enjoyed the experience at Whisper Rock and I'm really excited about continuing my work in course design on a wider scale," said Mickelson.

"The properties we're involved with are magnificent golf development settings and the variety of locations and terrains offers a great challenge for our team. We spent a lot of the past six months working on these projects and are excited to make this announcement."