THE smooth success enjoyed by Scottish racing suffered a blow yesterday when Morag Gray resigned as chief executive of Hamilton Park after a split with the rest of the board over TV rights.

Gray, who is also secretary of Scottish Racing, the group which oversees the five tracks in this country, was keen to see the Lanarkshire course join the At The Races channel, which is to begin free-to-air broadcasting in the near future. How-ever, the board opted to join the rival channel, Racing UK, which is to be launched tomorrow.

''I felt it was only right that I should resign,'' said Morag, ''I am proud of what has been achieved at Hamilton Park, alongside racing manager Hazel Peplinski. I would like to thank the great staff for all they have done and wish the racecourse continued success.

Sir Ian Good, chairman of Hamilton, spoke of his disappointment at the situation. ''I regret Morag's decision but understand her position.''

Morag will work a three-month period of notice and a successor will be sought as soon as possible.

Racing UK, backed by most of the major courses, at first was to be a subscription channel but the decision to go the free-to-air route with the prospect of switching to subscription at a later date. Their argument is that they will thus keep control of their own media rights.

The rivalry has split racing opinion, with many feeling that the threat to abandon the free-to-air policy, albeit at a later date, is bound to cost the racing business customers and a fall in income.