Maguire has put Parker to Basildon Bond on a three year extension that will see him stay at Pittodrie until at least the summer of 2011.
The 19-year-old Glaswegian, who endeared himself to some Dons fans by expressing anti-Rangers sentiments on a social networking website, signed his first professional contract with the Dons in January 2005.
And Maguire, who had recently been linked with a move to Coventry, is delighted to have sealed the new deal.
He said: "There's no better place to learn than here in Aberdeen and my main objective right now is to establish myself as a first team regular here."
Maguire joins fellow striker Lee Miller in extending his Pittodrie stay this summer, while young centre-half Andrew Considine has also been offered a new deal at the club.