Owner Mike Ashley was expected to decide by the end of this week whether to accept one of the bids currently on offer or continue running the Magpies for another season.
However, talks with local businessman Barry Moat and two other consortia are continuing as Ashley looks to strike a £100million deal for the club he bought for £134.4million just over two years ago.
While the club's ownership has been up in the air, Newcastle have been unable to make significant moves in the transfer market, with a loan deal for Manchester United's Danny Simpson their only summer signing so far.
A decision must therefore be made soon for them to bring in any more new additions before the transfer window shuts.
Manager decisionIn recent months, Ashley has been the target of angry Newcastle fans, who are hoping for a change of ownership and the installation of a new manager.
Many favour Alan Shearer, who failed to save the Magpies from relegation in a short-team stint at the end of last season, and he would be appointed by several of the competing consortia.
Should Monday's announcement be that Ashley has decided to take the club off the market for the second time after a lengthy - and ultimately futile - search for a buyer, he will then face a decision over his manager.
It is understood Ashley believes greater managerial experience is needed, and the Magpies have sounded out a series of potential bosses to succeed Chris Hughton.
The caretaker boss has received the backing of several players following a positive start to their Championship campaign and has insisted he is happy to remain in charge for as long as his services are required.