Sunderland have been granted permission to speak to Preston manager Simon Grayson as they step up the search for David Moyes' replacement.
The Lancashire club revealed on Thursday afternoon that they had been contacted by their Sky Bet Championship rivals and have given them the go-ahead to open negotiations.
A statement from Preston read: "Preston North End have today been contacted by Sunderland Football Club to ask permission to speak to Simon Grayson in relation to their vacant managerial position.
"Having spoken to Simon, he has asked permission to speak to the Black Cats and therefore the club had no option but to allow these conversations to take place with a compensation package already guaranteed in his contract.
"Whilst these talks are ongoing, Steve Thompson will be in charge of first team affairs.
"The club will make no further comment at this stage."
Grayson has been installed as the bookmakers' favourite to take over at the Stadium of Light in recent days with Derek McInnes having turned down the chance to manage the club and a series of other potential candidates, including former United States boss Jurgen Klinsmann and ex-Leicester manager Nigel Pearson, having distanced themselves from the vacancy.
Chief executive Martin Bain has been charged with the task of finding a replacement for Moyes, who resigned on May 22 in the wake of the club's relegation from the Premier League.
However, his efforts have been hampered by ongoing discussions over the club's ownership with chairman Ellis Short having spoken to German and American consortia.
The search for a new manager was put on hold after McInnes had rejected the Black Cats' overtures with the club engulfed in uncertainty.
But whether or not those discussions eventually come to fruition, time has become increasingly pressing with the players having returned for pre-season training on Thursday morning with no-one in the hot-seat and no new signings made.
In addition, several members of the squad are still to be offloaded despite keeper Jordan Pickford having left for Everton, striker Jermain Defoe expected to formally join Bournemouth at the weekend and Fabio Borini close to sealing a move to AC Milan.
Work is continuing behind the scenes too with chief football officer Simon Wilson and chief scout Mick Doherty set to leave in an overhaul of the club's recruitment set-up.