AS REPORTED HERE ON manchesterunitedMAD.NET LAST WEEK with the Headline..."Moyes To look To Barca again for magic in the midfield"
Press Association Sport understands the bid was submitted Monday evening Sydney time and thus so far there has been no response.
If the deal did go through it would represent David Moyes' first significant signing as United manager.
United were heavily linked with the former Arsenal skipper earlier in the summer, although at the time Fabregas claimed his intention was to remain with Barcelona.
Moyes then turned his attentions to Fabregas' Barca team-mate Thiago Alcantara.
At one point it seemed as though a deal for the Spain Under-21 star was nearing completion.
However, at the 11th hour Pep Guardiola stepped in and Thiago has now agreed to join Bayern Munich.
Fabregas does appear to be in a similar position to Thiago in that his World Cup place could come under threat if he does not play regularly for Barcelona following their ?50million acquisition of Brazilian superstar Neymar.
Barca are unlikely to let Fabregas go willingly, having nurtured the player through his formative years, only for Arsenal to sign him as a 16-year-old in 2003.
Fabregas spent eight years with the Gunners, making 303 appearances and ending up as club captain, before returning to the Nou Camp in 2011.
Source: PA
Source: PA