Sunderland have been granted permission to speak to Aberdeen manager Derek McInnes and his assistant Tony Docherty.
Aberdeen are understood to want around £1m in compensation for the Scot, who has two years left on his contract at Pitodrie, and Sky sources understand a deal is close to being agreed.
McInnes will travel to Sunderland for talks at the Stadium of Light once he returns from his holiday in the USA.
Aberdeen confirmed: “Early this afternoon, Sunderland FC agreed to meet all the contractual obligations for both Derek McInnes and Tony Docherty and they have, reluctantly, been granted permission to speak with both of them about the vacant managerial position at Sunderland.”
Sky sources reported on Tuesday that the Black Cats had made a formal approach for the 45-year-old, who led the Dons to a second-placed finish in the Scottish Premiership this season.
An unscheduled board meeting was held at Pittodrie on Tuesday to discuss the deal.
Sunderland want McInnes as to succeed fellow Scot David Moyes, with known admirer Walter Smith having helped Black Cats chief executive Martin Bain, formerly of Rangers, select a shortlist.
Despite a 2-1 Scottish Cup final defeat by Celtic, McInnes further enhanced his reputation with his tactics and approach against the Scottish champions, until substitute Tom Rogic capitalised on tired legs to net a stoppage-time winner at Hampden Park.