Kristoffer Ajer has completed a medical with Brentford ahead of his £13.5million transfer from Celtic.
The newly-promoted side are keen to add a centre back to their ranks before the top-flight campaign gets underway and have been in talks over Ajer in recent days.
The Norwegian went public with his desire to leave Celtic at the start of last month and he had attracted interest from the likes of Newcastle, Norwich City and Bayer Leverkusen.
Celtic rejected a £10m bid from Norwich but are now poised to bank a sizeable sum for a player in the final year of his contract.