The 24-year-old Belgium international scored 25 Premier League goals last season.
United, who have been chasing Lukaku for most of the summer, will not now be pursuing their interest in Real Madrid’s Alvaro Morata.
The move for Lukaku is not connected to talks aimed at taking United forward Wayne Rooney to Everton.
Jose Mourinho’s side are hopeful of concluding a deal in time for Lukaku to join the squad before they depart for a pre-season tour to the United States on Sunday.
The striker was on a list of forward options Mourinho gave to executive vice-chairman Ed Woodward before the end of last season.
It had been thought Lukaku would return to his former club Chelsea, who he joined from Anderlecht in 2011.
The striker was sold to Everton for £28m by Mourinho during the Portuguese manager’s second spell in charge of Chelsea in 2014.
Lukaku is a client of agent Mino Raiola, who also looks after Paul Pogba, Zlatan Ibrahimovic and Henrikh Mkhitaryan – three players all signed by United last summer.
The Belgian turned down the most lucrative contract offer in Everton’s history in March and later said: “I don’t want to stay at the same level. I want to improve and I know where I want to do that.”
culled from BBC Sports