THE percentage of Bolton pupils gaining the highest GCSE grades has slipped slightly despite a small national rise.

School performance league tables published today show that the proportion of candidates achieving marks A* to C this summer was 41.3pc, compared with 43pc last year.

At the same time there was a slender improvement in the national average from 48pc in 1999 to 49.2pc, which left Bolton ranked 100th out of 150 English education authorities.

Bury came 34th in the national table, but there too the percentage of highest passes was down slightly from 54pc to 53pc.

Bolton's education chiefs are upbeat about schooling in the town and insist the dip is just a minor blip set against the positive picture identified by Ofsted inspectors who praised the town's local education authority.

"I haven't seen any complacency from schools," said David Abrams, LEA adviser with responsibility for assessment. "They are setting incredibly challenging targets and even the best are striving to get better." The most improved school was Lord's College in Manchester Road where the percentage of pupils gaining grades A* to C rocketed from 44pc in 1999 to 6pc this year.

The college leapt six places up the league table from 10th to fourth.

Principal Denise Whittle said: "We are thrilled to bits. But it's not that other schools aren't trying just as hard as we are -- it's just been a good year. Nobody can guarantee it will be the same next year."

Bolton School's Boys and Girls divisions again top this year's GCSE tables, with 100pc and 98pc of A* to C passes respectively.

And the school emulated last year's clean sweep by heading the A Level tables as well.

Top state school for GCSEs was Canon Slade with 74pc grades A* to C while the Withins School was bottom of the table with only 11pc, a fall of 8pc from 19 pc last year. Critics question value of publishing exam figures THE league tables have faced a barrage of criticism since they were introduced by the Conservatives and adopted by Labour, with even schools in top positions questioning their value.

They argue that because schools draw from radically different catchment areas, it is not fair to judge them by the same benchmarks.

Critics argue that the tables have no "value added" element showing how pupils have improved in their time at a school.

Immeasurable features such as a school's ethos and extra-curriculur activities --along with qualifications including NVQs, certificates of achievement and basic skills awards -- also fall outside their scope.

Among those urging caution in reading the tables is Father Mervyn Williams, head of Thornleigh Salesian College, despite his own school coming seventh in Bolton with an above average 52pc A* to Cs. He said: "The most important thing is that parents get a rounded view of what a school is like.

"All the secondary schools in Bolton provide good educational value for pupils.

"I would hope people are becoming more sophisticated than thinking the school at the top must be the best and the school at the bottom must be the worst. That simply isn't the case."

David Abrams, LEA adviser with responsibility for assessment, said: "Even those schools which may appear not to be high achieving will be doing a lot of other work."