United are understood to have notified the Molineux hierarchy of their intention to trigger the release clause for Brazil international Cunha.
However, the two sides are involved in a stand-off as to how the payments should be structured for the 15-goal striker. It is understood that United want to pay the £62.5m fee over five instalments over five years.
However, Wolves are insistent that the fee must be paid over two years and in three payments – as stated in the release clause in the 26-year-old’s contract.
The club have long maintained that Cunha would not be allowed to leave on the cheap – and are sticking to their guns over payment terms.
It comes as Cunha sent a leaving message to Wolves on social media.
He said in a post on Instagram: “Wolves, what can I say to you?
“What an incredible season. We didn’t get to where you deserve to be, but we did everything we could to make you proud. I love these guys.
“Individually, it was the best season of my life. All of this was only possible because of all the dedication and love I have for this club. I became the Brazilian with the most goals in a Premier League season, along with @roberto_firmino and @gabriel.martinelli.
“I made mistakes and got things right, but always because I lived this club so much. All I ever wanted was to do the impossible for Wolves. Another one is over.“And thank you all for all the affection.”