The Red Devils courted the ex-Arsenal star last year, but despite making several offers for his signature they were unable to lure him back to the Premier League.
However they have since remained keen on the silky playmaker, and are now ready to launch a new offer amid rumours that he is available.
The 27-year-old is said to have been told by Barca that he is free to look for a new club this summer, with the Nou Camp side set to undergo a huge change this off-season.
Fabregas has been a regular under Tata Martino over the course of the campaign, but with the coach looking like he could leave the Catalan giants the midfielder’s role is somewhat uncertain.
United are ready to pay up to £45m to lure the World Cup-winner to Old Trafford and offer him wages of over £200,000-per-week as they prepare to invest in their first-team on the back of a disastrous 12 months.
Louis van Gaal – who is set to be named as United’s new boss – is known to be keen to bolster his prospective engine room, and a player of Fabregas’ quality and experience would appeal to him.