West Ham have agreed a £13.5m fee with Bayern Munich for right back Noussair Mazraoui plus £3m in add-ons.
26-year-old Mazraoui has spent two seasons at the Allianz Arena, having joined on a free transfer from Ajax in the summer of 2022.
The full-back came through the ranks at Ajax, where he played under current Man United boss Erik ten Hag.
He was also a member of the Morocco team that overcame the odds to reach the semi-final of the 2022 World Cup.
There had been reports of United circling the player but now West Ham are nearing his signature.
Bayern Munich's Noussair Mazraoui is set to join West Ham for an initial £13.5m plus £3m
West Ham, now managed by Julen Lopetegui, have made three major signings so far in this transfer window.
Exciting youngster Luis Guilherme joined the club from Palmeiras, while goalkeeper Wes Foderingham arrived on a free transfer following his departure from Sheffield United.
West Ham also secured the signing of Max Kilman from Wolves, who is set to boost their defensive ranks.
The Hammers are also chasing Aston Villa striker Jhon Duran, but their offer of £32m plus 18-year old midfielder Lewis Orford, was rejected.