Birmingham City are the latest club to express an interest in signing Denny Johnstone, although the teenager will not be allowed to leave Celtic without a compensation fee being paid.

The 19-year-old striker, who has played for the Scotland Under-19s, was initially a target for Dundee United but the club baulked at the demand that a fee be paid first. Celtic are entitled to a development fee for the youngster.

Birmingham have asked to sign Johnstone in exchange for a sell-on clause being part of the deal but Celtic are yet to agree. "Celtic are demanding compensation," said Lee Clark, the Birmingham manager.