Bulgarian club CSKA Sofia have filed a lawsuit against Manchester United in regards to unpaid fees involving Dimitar Berbatov.

It is reported that Sofia are owed £450,000 for sell-on fees from the deal that saw Berbatov join United from Tottenham Hotspur.

The two parties are said to have met on several occasions to settle the dispute, but Sportal has reported that United have said that "nothing will be wired to CSKA Sofia."

Sofia have engaged the services of international sports lawyer Ian Blackshaw to help with their case.