Motherwell have agreed a fee with Celtic of £3m plus add-ons for midfielder David Turnbull.
The Fir Park club rejected bids, one of £2m, from Celtic and Barnsley this week for the 19-year-old.
Turnbull was last month named Scottish Football Writers’ young player of the year after scoring 15 goals in his breakthrough season at Fir Park.
“Motherwell has reached an agreement with Celtic for the potential transfer of David Turnbull,” the club confirmed.
The deal almost doubles Motherwell’s previous club record sale of £1.7m for Phil O’Donnell to Celtic in 1994.
Scotland Under-21 cap Turnbull was free to talk to clubs in January when his deal was down to the final six months, but instead opted to sign a new contract until summer 2021.
Motherwell’s statement added: “The academy graduate has been given permission to speak to the club. Should the deal go through, the value of the transfer will vastly exceed our previous record fee received.
“We have rejected several seven-figure offers for David in recent weeks, with clubs the length and breadth of the UK speaking to us about him. It is clear from that the fee we stand to receive fully maximises his potential value.
“We have continued to stand by what we believe is a fair value for David. In light of the negotiating stance we have adopted, the money we stand to receive will be transformational for us as we continue to operate as a fan-owned club.”