Kerr's contract expires at the end of the season and it is understood North End manager Alan Irvine took a shine to the player when scouting former United keeper Grzegorz Szamotulski.
Irvine was in the stand for Dundee United's CIS Cup Final defeat to Rangers and although Kerr gifted the Ibrox side a crucial equaliser, Irvine was sufficiently impressed to offer the player a contract.
With Aberdeen and Hearts also in contention for the 25-year-old's signature, United boss Craig Levein is understandably concerned.
"I'm not surprised clubs are interested in Mark.
"I've spoken to his agent and would obviously like to do something to make him stay with us, but it all depends."