The Spain goalkeeper had been in a stand off with Old Trafford’s hierarchy over their refusal to make him the highest paid player at the club on £450,000-a-week.
And while the latest offer is believed to be well below that, in the region of £375,000-a-week, the length of the contract made it impossible to turn down.
It means his future has been secured until the age of 34, which he is unlikely to have been offered at Paris Saint-Germain or Juventus.
De Gea was determined to be rewarded for his status as United’s most consistent player over the past six seasons - but he also wanted to be convinced the club was capable of competing for the biggest prizes again.
Sources close to him insist personal ambition remained his priority.
He has bought into Ole Gunnar Solskjaer’s vision of building a young and hungry team in the traditions of Sir Matt Busby and Sir Alex Ferguson.
But it was also Solskjaer’s personal touch that was influential.
It is understood De Gea was at his lowest ebb at United when he suffered a dramatic loss of form in the final weeks of the season.
He was responsible for costly errors against Arsenal, Barcelona and Chelsea as Solskjaer’s side missed out on Champions League qualification.
But Solskjaer’s refusal to drop him amid concerns his contract situation had become a distraction made a huge impression on the 28-year-old.
His relationship with goalkeeping coach Emilio Alvarez, who took him under his wing at Atletico Madrid, is also a key factor.
He is set to sign his new deal when United return from their tour to Australia, Singapore and China.
That will see United sign off a loan move for Dean Henderson - most likely to Sheffield United.