Sunderland owner Ellis Short is reportedly willing to accept an offer of £85m to sell the club and is still locked in talks with two interested parties.
The Black Cats chief, involved at the Stadium of Light for close to a decade, is keen to flog the Black Cats following relegation to the Championship.
According to The Sun, Short held a meeting with German bidders in London earlier this week, but they are only prepared to offer £50m.
An American consortium is also said to be weighing up an offer, meanwhile, with Short giving both potential buyers until the end of the month to agree a deal.
Sunderland have put their search for a new manager on hold until the club is sold, having recently missed out on top target Derek McInnes.