Ashley bought the club in 2007 but could not recoup the £134.4m he paid
Newcastle owner Mike Ashley has ended his attempt to sell the club and will invest a further £20m in the next week.
The club confirmed on Tuesday that Barry Moat's bid had fallen through after he failed to meet the £80m price.
New plans include selling the naming rights to St James' Park - the club's home since 1892 - to increase revenues.
Ashley first put the club up for sale in September 2008, withdrew it in December, but announced he wanted to sell again after relegation in May.
Moat was the latest in a number of prospective buyers unable to complete a deal for the Championship leaders.
A Newcastle statement on Tuesday said: "Mike Ashley is totally committed to the future success of Newcastle United and will be focused on gaining promotion back to the Premier League. Mike will put a further £20m into the club this week."
At the same time, Chris Hughton was confirmed as the club's permanent manager.
"Whilst confirming these two matters, Newcastle United now aims to move forward on and off the pitch," the statement continued.
"The club aims to maximise its commercial revenues; this includes renegotiating its club sponsor and kit deal, which expire at the end of this season, as well as welcoming offers for the stadium naming rights for next season."
St James' Park, which has been used for football since 1880, is the oldest and largest stadium in the North East and will be used as a football venue for the 2012 Olympics.
BBC Radio 5 live football commentator John Murray said: "Many of Newcastle's supporters will be sceptical and also disgruntled that Mike Ashley's ownership of - and relationship with - the club is set to continue.
"And however much stadium naming rights are part of football in the 21st century, let's see how many of them refer to St James' Park as anything other than that once a sponsor's brand is nailed onto it.
"But with over a quarter of the league season gone, Newcastle a point clear at the top of the table and the economy emerging from recession, you can't help but suspect the club may not be off the market for long."
Ashley bought Newcastle in 2007 for £134.4m but has endured a torrid time in charge of the club following his purchase, culminating in their relegation from the Premier League last season.
After making the popular move of replacing Sam Allardyce with Newcastle legend Kevin Keegan in January 2008, support for Ashley nosedived as he and director of football Dennis Wise fell out with Keegan.
In September 2008, Keegan resigned and Ashley made a statement announcing he was selling the club, while Joe Kinnear was the surprise choice to take charge of the team.
In December 2008, the club was taken off the market but the team continued to struggle in the Premier League, and two months later Kinnear was given leave following heart trouble.
With relegation looming, Ashley called on another Newcastle legend to try to rescue the club but former England captain Alan Shearer could not prevent relegation in his eight games as interim manager.
Hughton was on the coaching staff throughout and has since guided the team to the top of the Championship after 14 games, but off the field Newcastle have been ordered to pay Keegan's costs in his successful claim for constructive dismissal.
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