Chelsea announced on Saturday morning that a group led by US investor Todd Boehly had agreed to buy the club.
On Monday, the formalities should be done.
The Premier League club was sold following a 12-week ordeal and with four days left before the government's operating licence expired.
The Premier League and the UK government approved the Boehly company, which will be mostly funded by the Clearlake Capital investment firm, to take over from sanctioned Russian oligarch Roman Abramovich on Tuesday night.
The sale was approved by authorities in Portugal, where Abramovich has citizenship, early Thursday morning, and the club has officially acknowledged that the £4.25 billion deal has been completed.
"Chelsea Football Club can confirm that a final and definitive agreement was entered into yesterday night to sell the Club to the Todd Boehly/Clearlake Capital consortium," says a statement on the club's official website.
On Monday, the transaction is anticipated to be completed. At that time, the Club will provide additional information."