Sky Sports News understands that Hull City have given Michael Turner permission to talk with Sunderland.
The Tigers have made no secret of their desire to retain the services of their commanding centre-half, but they may be forced to accept defeat in their efforts.
Sunderland boss Steve Bruce has been chasing the 25-year-old for some time and appears to be closing on his man.
The Black Cats will now be hoping a deal can be pushed through before the transfer window slams shut on Tuesday.
Turner has spent the last three years with Hull, helping the club to clamber into the Premier League.
He played an integral role in their battle to beat the drop last term and was rumoured to be in the thoughts of England boss Fabio Capello.
Reports of interest from Tottenham and Liverpool have surfaced at regular intervals over the last12 months, but it appears that it is Sunderland who lead the race for his signature.