If Mourinho does sign the new deal and remain at Old Trafford, it will make his time at Old Trafford the longest tenure of his career.
Mourinho's £250,000-a-week wages are set to remain the same but there is said to be some increased bonuses included in the new deal.
The final details are however still to be agreed.
Mourinho himself is determined to return the position of MU to the ranks of elite clubs in Europe.
Two men were charge with public order offences last season, leading both United and Liverpool to release a statement calling on fans to help "eradicate any offensive or discriminatory behaviour".
Mourinho, 54, initially signed a three-year contract with the Red Devils, and he looks set to be rewarded after a fine start to the 2017-18 season, which sees his side second in the Premier League, behind Manchester City only on goal difference.
Chelsea are now preparing for their Premier League trip to Crystal Palace on Saturday as they look to bounce back from their 1-0 defeat by Manchester City before the global break.
Owners the Glazer family have made it clear they are willing to back him to achieve that.
His relationship with executive vice-chairman Ed Woodward is also said to be a strong on with the club chief thinking Moutrinho is the best thing they have to Sir Alex Ferguson.
It is a stark contrast to previous years, where the likes of David Moyes and Louis van Gaal failed to get the Old Trafford outfit firing.
Pakistan desperate to win ODI series against the Lions
The trophy unveiling ceremony of the Pak-Sri Lanka One Day series was held at the Dubai International Cricket Stadium on Thursday. Besides, Pakistani top bowler Mohammad Amir could not participate in ODI series though at the first time, he was in the squad.