Graeme McDowell has agreed the first of a series of mega-buck contracts which in the New Year will establish him as one of the top earners in world golf.

US Open champion McDowell has accepted a “multi-year” deal worth a reputed $3million per annum with Japanese equipment giant Srixon.

A year of spectacular success on the world's fairways had already established McDowell as the highest new entry at No 14 in the sport's unofficial ‘rich list’ — when Golf Digest's top 50 earners in 2010 was published on Thursday. As his contract with Callaway did not expire until midnight last night, McDowell's new equipment deal with Srixon is not included in the $9.7million which Golf Digest estimate Ulster's world No 7 banked on and off the course in the past 12 months.

Rory McIlroy has soared 11 places to 24th with $8.2million.

McDowell has agreed to play with the Srixon golf ball, wear their hat and glove and, along with his choice of Srixon clubs, use wedges produced by sister company Cleveland, the world-leaders in this department.