The 27-year-old is out of contract with the Dons in the summer and will move to Deepdale in time for next season unless compensation can be agreed between Preston and Aberdeen during the January transfer window.

Preston chairman Derek Shaw told the club's official website: "We made Aberdeen an offer earlier this month which was not accepted.

"I understand that Aberdeen have agreed a fee for two of their players with another Championship club, however Michael has chosen to come to Preston and we are delighted with that.

"Ideally we would like to agree compensation with Aberdeen in the January transfer window and Michael can start his Preston North End career sooner rather than later, however if that doesn't happen then Michael will be our player in time for pre-season in the 2008/09 campaign."