The Blades were hoping to be sold to Americans Steven Rosen and Helmy Eltoukhy.
The duo already have a full agreement with the EFL and felt that they had a deal with Abdullah as well.
Per The Mirror, he is now refusing to sign off on the £100 million takeover, as he wants more money.
Rosen and Eltoukhy, who have links to Resilience Capital Partners, have a plan for taking the club forward.
They are now hoping the takeover can go through before the winter transfer window.
- Get breaking football news faster with the new Tribal Football app! Download now on iOS and Android to stay ahead of all the latest transfers and football updates. Download now: App Store, Google Play
