But whether the England midfielder is actually bound for the Catalan club remains in serious doubt.
Unlike other potential suitors such as Italy's AC Milan or Real Madrid, Barcelona are not in next season's Champions League, a competition Beckham has become used to gracing every season with United.
With Barcelona not even guaranteed a direct entry into the UEFA Cup next season after a yet-to-be-completed disappointing Spanish league campaign, the England captain could end up playing in the Intertoto Cup.
United's acceptance of the Barcelona bid is also subject to two huge conditions -- namely that the man who made the so far unspecified offer, Joan Laporta, wins his bid to become club president on Sunday and that they can then agree personal terms with Beckham.
Laporta is gaining ground on his main rival, Lluis Bassat and in terms of an electioneering ploy, his 'deal' with United could prove a masterstroke.
But even then Beckham, owner of one of the most marketable images in world sport, must agree personal terms with Barcelona. His management company SFX indicated on Tuesday he had no plans to speak to Laporta and that he is disappointed to be used as a "political pawn" in the Spanish club's elections.
United know to their cost how complex and protracted such talks can be after hammering out a new deal with Beckham in May 2002.
That deal, which runs until the end of June 2005 and was worth a reported 100,000 pounds per week to Beckham, was held up by the vexed issue of his image rights.
RUINED HOLIDAY
What is clear, however, is that the United-Beckham love affair is over, something that will leave many of the club's fans heartbroken.
United's unusual step of issuing a statement on their website about an ongoing transfer negotiation confirmed that they are actively planning for life after Beckham.
However the club did not bother to announce the news of the Barca 'deal' to the London Stock Exchange on Tuesday -- perhaps suggesting they consider the matter far from resolved.
The English champions need to fund a move for Paris St Germain's Brazilian midfielder Ronaldinho and Beckham's sale would probably raise at least 30 million pounds ($49.70 million) - an enormous sum in an otherwise deflated transfer market.
With AC Milan indicating that the asking price may be too high, the temptation for United to sell their prize asset now, two years before he can leave for nothing, is huge.
As for Beckham, his comments in a U.S. newspaper on Monday that he would stay at United "as long as they want me" suggest he has also come to the realisation that the club may wish to cash in their prize asset.
The season just finished was not the 28-year-old's happiest, despite the club reclaiming the premier league crown.
His relationship with manager Alex Ferguson suffered when the team boss accidentally kicked a boot at his head in the Old Trafford dressing room after an FA Cup fifth-round defeat by Arsenal in February.
Beckham also lost his starting place in the United team during the title run-in, when they performed impressively without him, and he bid an emotional farewell to United fans after their last home game of the season against Charlton Athletic, prompting further speculation about his future.
After Tuesday's announcement British bookmakers William Hill cut their odds on Beckham leaving United before the start of next season from 5-6 to 1-3.
Going he may be, but predicting exactly where is a trickier bet entirely.
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