Bennett has been linked with a move to a host of Premier League sides but Fry - who expects to keep hold of his whole squad before the transfer deadline - insists that the only bid he has received was from the Blades.
He told the Peterborough Evening Telegraph: "The only dealings I've had over Ryan are with Sheffield United and Newcastle.
"Kevin Blackwell offered us a million when he was manager at Sheffield United, but we wouldn't even have taken that as a down-payment.
"Newcastle still do have a big interest and have asked us to keep them informed on Ryan.
"He is a player on a long-term four-year contract who is still nowhere near the finished article. He has started the season well and knows he has to keep performing with Gabriel Zakuani breathing down his neck."