Chelsea have signed Rangers' highly-rated 15-year-old midfielder Billy Gilmour, who has come through the Scottish club's academy system.
Sky sources understand the development fee being paid to Rangers will be £500,000 with additional payments due on the attainment of specific career milestones.
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Gilmour, who is regarded as one of the brightest young prospects in Scottish football, has played for the Rangers U20 side and has trained with the first team.
But despite the best overtures of manager Pedro Caixinha to persuade him to stay, the youngster has elected to take his chance with the English champions-elect.
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A Rangers statement read: "We can confirm that agreement has been reached for our U16 player Billy Gilmour to join Chelsea in the summer.
"The club's preference would have been for Billy to stay at Rangers but when he made clear his desire to move to the Premier League it was important that we maximised the commercial value for him. We believe we have done this.
"The agreement will provide Rangers with a significant sum for a young player who has yet to play first-team football, and further significant amounts could be due based on milestones being reached.
"We are pleased with this outcome and believe this deal represents good value for Rangers.
"That he was sought after by many Premiership clubs, and indeed a number of the largest clubs in Europe, further demonstrates the quality of player now being produced by the Academy. Everyone at Rangers wishes Billy well for his future."
Gilmour is not the first to head south from Glasgow to west London at such a tender age; Islam Feruz left Celtic for Chelsea at 16 in 2011 but has since spent the bulk of his time out on loan and has yet to make a senior appearance for the Premier League club.