But West Ham cast doubt on the proposed move by insisting there is no agreement in place for him to join the champions.
And the Premier League are likely to back West Ham in their stance.
Hammers chairman Eggert Magnusson said in a statement: "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."
Tevez is currently in Venezuela on Copa America duty and played in Argentina's win over Paraguay.
The situation is further clouded by the fact United believe he is not under contract to West Ham any more and that they merely had an option to sign him for a further three years.
West Ham are adamant he is still under contract and will be so until 2010.
Tevez's camp had hoped to have set up a deal worth a possible £30million and although there had been close to an agreement with the Red Devils, the Premier League have demanded that any transfer is handled by the Hammers and will block the move unless they are satisfied the transfer fee will go to West Ham.
The league accepted in April that West Ham had terminated all agreements with Tevez's agent Kia Joorabchian - and will keep a watchful eye on any transfer to ensure that the club keep their promise.
A Premier League spokesman said: "As far as we are concerned any deal to take Carlos Tevez away from West Ham has to be done directly with the club."
A statement from Joorabchian's lawyers said: "The circumstances surrounding Carlos Tevez's relationship with West Ham have been well documented in the media and footballing world.
"We confirm that Carlos Tevez has, with the knowledge and permission of West Ham United Football Club, been in discussions with other clubs.
"Subsequently, personal terms have now been agreed with Manchester United Football Club.
"Carlos Tevez's representatives will work during the course of next week so that a move to Manchester United can be finalised as quickly as possible.
"The process for finalising the player's registration with Manchester United will be undertaken in accordance with appropriate procedures."
For their part, United are eager to distance themselves from any suggestion they have acted incorrectly, either in negotiating with the player or trying to push through a deal with Joorabchian.
United's frustration at getting so close to signing a major star without being able to finalise the transfer is obvious.
Unless a compromise can be brokered, the issue seems to be heading for the courts, to determine once and for all who owns Tevez's registration.
"We have acted in good faith," argued a United spokesman.
"Carlos Tevez was given permission to speak to us and do a deal."
