Manchester United may have to be patient in their bid to sign striker Carlos Tevez from West Ham United, BBC Sport understands.
Tevez has his heart set on a move to Manchester United
United boss Sir Alex Ferguson says the club are close to signing Tevez.
Ferguson said: "We are in negotiations and want to make sure there are no side issues. The essential parts are agreed. Hopefully it will be finalised soon."
But BBC Five Live has been told the Premier League could take weeks to finalise the move for the 23-year-old.
The Premier League says the transfer must be "done directly" with West Ham rather than his agent Kia Joorabchian.
According to the Argentine's representatives personal terms were agreed with United last week.
Ferguson added: "Club solicitor Maurice Watkins has been working on it for a month, maybe more, to make sure the deal is perfectly clear.
"To be honest, I thought it would have all been sorted by the weekend just gone. It must be the Premier League that is holding it up.
"From what chief executive David Gill and Maurice said, everything was ready to go. Unless something is being held back from us, I don't know of anything that is holding it up."
However, last week West Ham chairman Eggert Magnusson insisted Tevez is a registered Hammers player and is expected to return for the new season.
But Joorabchian's lawyers say the deal has progressed with the "knowledge and permission" of the Upton Park outfit.
Tevez has made no secret of his desire to move to Old Trafford, a proposed transfer he has described as a "dream", and it appears it has taken a step closer to being realised.
He was involved in the saga that led to West Ham being fined £5m for breaching transfer rules, although they crucially escaped a points deduction.
The Premier League wants to ensure Joorabchian is not paid any of the fee after previous questions over the Argentine forward's "ownership".
And the waters are further muddied by the fact that West Ham, who insist they cut all ties with Joorabchian after they were fined in April, expect Tevez to return to east London after he concludes his international duties at the Copa America in Venezuela.
Magnusson said earlier this month: "Carlos Tevez is a registered West Ham player, contracted to the club until June 2010.
"There is no agreement with West Ham for Carlos Tevez to leave the club and we expect him to return in time for next season's preparations.
"No decision on his future can be reached without the agreement of West Ham."
One possible avenue would be for West Ham to be paid a transfer fee and then agree a compensation figure with Joorabchian for breaching contracts with his company, Media Sports Investments (MSI), when the Hammers terminated third-party agreements following their fine.
However, it is understood the League would want a substantial chunk of the transfer fee to remain at West Ham rather than it all be handed over to MSI in compensation.
If that was the case, they could be accused of merely covering up the third-party agreements that have caused so much controversy.