Romelu Lukaku is set to have a medical with Manchester United after they agreed to pay Everton an initial £75m for the Belgium striker.
The deal for the 24-year-old, initially reported by BBC Sport on Thursday, is believed to include £15m in add-ons.
United said they were "delighted" to agree a deal, and the move was "subject to a medical and personal terms".
Chelsea had matched the Red Devils' bid, but appear set to miss out on re-signing their former player.
The Blues were not willing to match the fees Lukaku's agent, Mino Raiola, would earn if the forward moved to Old Trafford.
"A further announcement will be made in due course," added United.
Red Devils boss Jose Mourinho was manager of Chelsea when they sold Lukaku to Everton for £28m in July 2014.
The Belgian scored 25 Premier League goals last season, and United have been chasing him for most of the summer.
They are keen to conclude a deal before they depart for a pre-season tour to the United States on Sunday.
Wayne Rooney is not expected to be part of United's squad for the trip as he looks set to return to Everton on a free transfer. The two deals are not connected.
Lukaku was 18 when he signed for Chelsea from Anderlecht in August 2011 for a fee reported to be about £20m.
He made just one Premier League start for the club and spent time on loan at West Bromwich Albion and Everton before sealing a permanent move to Goodison Park.
Lukaku turned down the most lucrative contract offer in Everton's history in March, thought to be worth £140,000 a week, 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."
Lukaku in stats
With two goals against Hull City in March, Lukaku became the first Everton player since Gary Lineker in 1985-86 to score 20 league goals in a season.
Lukaku is also only the fourth player to score more than 80 goals in the Premier League before turning 24 (after Michael Owen, Robbie Fowler and Rooney).
He has scored more goals than any other Everton player in Premier League history (68).
Lukaku is one of only three players to have scored more than 10 goals in each of the past five Premier League seasons (alongside Olivier Giroud and Sergio Aguero).