This will save the councils nearly Pounds 5 million. Another 135 cases are lodged with the tribunal in Glasgow but are now expected to fall.
An industrial tribunal in Glasgow and the employment appeal tribunal in Edinburgh had ruled eight instructors in the former Strathclyde Region, led by Jessica Marshall, were justified in arguing for similar pay for similar work under the Equal Pay Act.
It is the second defeat for equal pay cases involving education. Tribunals twice accepted that nine women members of the Scottish Secondary Teachers' Association had a case for parity with principal teachers while carrying out their duties in a department with no head.
Strathclyde and its 12 successor authorities appealed successfully to the Court of Session. The SSTA will attempt to reverse the Scottish judges' opinion in the Lords in 10 days' time.
The instructors, seven of them women, argue that they should be paid the same as teachers for doing work councils accepted was similar. However, the authorities contended that teachers had higher qualifications and longer training than instructors and were forced by legislation to pay teachers a certain rate. No similar legislation underpins instructors' pay on local authority conditions of service.
Linda Marsh, the councils' spokeswoman, said: "It has underscored the point we have always made that this is nothing to do with sex discrimination and it is simply a ruse whereby people are attempting to circumvent the regrading system or pre-emptively get large pay rises that the councils cannot afford in this climate."