Japan’s Softbank has cancelled its planned sale of U.K. chip company Arm to U.S. technology group Nvidia.

The two organizations decided to terminate the transaction “because of significant regulatory challenges preventing the consummation of the transaction, despite good faith efforts by the parties.”

As part of the agreement, which both companies signed in 2020, Softbank will retain a $1.5 billion non-refundable deposit that Nvidia will pay.

In the future, Softbank will work towards listing Arm’s shares on the stock exchange by the end of March next year.

“We will take this opportunity and start preparing to take Arm public, and to make even further progress,” SoftBank chief Masayoshi Son said.

Since the deal became public, several authorities, including U.S., U.K. and EU regulators, have tried to stop it, and critics say the deal will put Nvidia’s competitors at its mercy, a move that effectively threatens healthy competition.