Their new deals will keep the duo at the club until the summer of 2013.
“Jon is an important member of the squad, our club captain,” United manager Peter Houston told the club’s official website.
“He has shown himself willing to play anywhere for the team but he is most important to the team as a striker.
“Sean brings plenty of experience to our young squad, is a model professional and I’m delighted he has agreed to extend his contract at the club.”
