The Saudi Public Investment Fund has walked away from its takeover of Newcastle United.
The PIF had been set to take an 80% stake in the Premier League club but has withdrawn its interest.
A statement from the group read: "An investment group led by majority investor the Public Investment Fund; PCP Capital Partners; and RB Sports & Media, announced today that it has formally withdrawn its interest in pursuing the acquisition of Newcastle United Limited and Newcastle United Football Club Limited."
PCP Capital and RB Sports & Media had been set to take a 10% stake each in the deal, which is understood to have valued the club at just over £300million.
The statement added: "With a deep appreciation for the Newcastle community and the significance of its football club, we have come to the decision to withdraw our interest in acquiring Newcastle United Football Club.
"We do so with regret, as we were excited and fully committed to invest in the great city of Newcastle and believe we could have returned the club to the position of its history, tradition and fans' merit.
"Unfortunately, the prolonged process under the current circumstances coupled with global uncertainty has rendered the potential investment no longer commercially viable.
"To that end, we feel a responsibility to the fans to explain the lack of alternatives from an investment perspective.
"As an autonomous and purely commercial investor, our focus was on building long-term value for the club, its fans and the community as we remained committed to collaboration, practicality and pro-activity through a difficult period of global uncertainty and significant challenges for the fans and the club.
"Ultimately, during the unforeseeably prolonged process, the commercial agreement between the investment group and the club's owners expired and our investment thesis could not be sustained, particularly with no clarity as to the circumstances under which the next season will start and the new norms that will arise for matches, training and other activities."
The statement continued: "As often occurs with proposed investments in uncertain periods, time itself became an enemy of the transaction, particularly during this difficult phase marked by the many real challenges facing us all from Covid-19.
"We feel great compassion for the Newcastle United fans with whom we shared a great commitment to help Newcastle United harness its tremendous potential and build upon its impressive and historic legacy while working closely with the local community.
"We would like to say that we truly appreciated your incredible expressions of support and your patience throughout this process. We are sorry it is not to be.
"We wish the team and everyone associated with it much good luck and success."
The takeover attempt has been dogged by criticism of Saudi Arabia's human rights record and its links to broadcasting piracy.
The league was warned by human rights group Amnesty International that it "risked becoming a patsy" if it allowed the takeover to go through.
The piracy question has also been a particularly thorny one, with the Premier League having repeatedly tried and failed to seek legal redress against illegal broadcaster beoutQ through the Saudi system, only to be thwarted on each occasion.
On Wednesday, Saudi Arabia appealed against a World Trade Organisation report which found that it had facilitated the activities of beoutQ.
Saudi authorities also suspended the broadcasting licence of beIN SPORTS, which meant there was no legal means to watch Premier League football in the country until 2022 at the earliest.
However, it is understood the Premier League's chief concern was setting a precedent in allowing a club to effectively become state-funded.
The PIF is a commercial entity and it sought to demonstrate to the Premier League that separation, but eventually grew frustrated at the lack of an end date as the league considered its application under its owners' and directors' test.
It is understood the new owners had been prepared to invest £250m in the club over five years, plus further funding for wider community projects in the city.