With the uncertainty over whether or not Ashley will sell the club ahead of the 2019-20 campaign, there appeared to be plenty of obstacles for both parties to overcome.
"It is with disappointment that we announce manager Rafael Benítez will leave Newcastle United upon the expiry of his contract on 30th June 2019," the club said in a statement.
"We have worked hard to extend Rafa's contract over a significant period of time, however it has not been - and will not be - possible to reach an agreement with Rafa and his representatives."
Former Liverpool and Real Madrid boss Benitez joined Newcastle in March 2016 but failed to save them from relegation from the Premier League.
The Spaniard stayed in charge and led them to promotion from the Championship, then stabilized the club with a 10th-placed finish on their return to the top-flight and then 13th last season.
"We would like to thank Rafa and his coaching team for their efforts over the last three years and their significant contribution to what has been collectively achieved," the club added.
"We would also like to thank our supporters, players and staff for their patience during a period of uncertainty.
"The process to appoint a successor will now begin."
(Reporting by Hardik Vyas in Bengaluru; Editing by Christian Radnedge)
