A spokesman for Sunderland AFC said the club was "dismayed" Jack Colback has agreed a deal with local rivals Newcastle United, saying the move "leaves a bitter taste in the mouth".
"Jack is a player we have nurtured and developed through our academy system since he was eight years old. We gave him the opportunity to become a professional footballer and are therefore extremely disappointed in the events that have led to his departure from the club"
“This wasn’t about money - the club agreed to all of the terms demanded of us during discussions and we were always led to believe that Jack wanted to stay with us. At his and his representatives’ request, final talks were put on hold until the club secured its top flight status.
"To our dismay however, we were subsequently never given the chance to negotiate with him to stay.
“For him to then leave the club that has supported him throughout his formative years in such a manner, with no chance for Sunderland to recover any of the significant investment that it has made in him as a player, has left a bitter taste."
More top news
The North East is to become an international centre for research and excellence into Spanish and Latin American art and culture .
The first major stage of the restoration of the Spanish Dome in Whitley Bay has been completed.
A new report has highlighted just how important heritage sites like Hadrian's Wall and Durham Cathedral are to the North East.