By Gary Eason
BBC News Online education editor
There has been a slight fall in the GCSE pass rate across the UK, to 97.6% of more than five million exam entries.
The final pass mark trend - the 2003 figure is provisional
The proportion of exam entries getting the top grades increased again, as it has done since GCSEs began in 1988.
The "gender gap" among the best students narrowed slightly, with boys' performance improving while that of the girls remained the same.
There was a big rise in the number taking business studies, while the decline in French and German continued.
The provisional overview of the results being delivered to most candidates on Thursday was published by the Joint Council for General Qualifications.
It shows the proportion of exam entries which achieved any grade, from A* down to G, was 97.6%, down from the equivalent 97.9% provisional figure of the last three years.
Entries getting top grades - the 2003 figure is provisional
This overall pass rate has tended to fluctuate a little. It was 96.6% in the first year, 1988, and peaked at 98.6% in 1997.
The figure for those getting the better grades, A* to C - the basis of the school performance tables later in the year - was 58.1%, up 0.2 on the same time last year.
That figure has been rising steadily. In 1997 it was 54.4%.
This year the increase was down to the very top grades, A* (up 0.1) and A (up 0.2). The proportion of entries getting a B fell by 0.1 point and those achieving C were unchanged.
In Northern Ireland, 69% of students' entries achieved the top grades - more than 11 points above England - although the overall pass rate was the same as elsewhere.
The boys' performance at A* to C in the province went up a whole point, year on year - five times the rise elsewhere.
In Wales, 59.7% achieved A* to C grades, the same as last year.
Girls tend to outperform boys in most subjects, the exceptions being economics and biology, chemistry and physics.
In terms of subject popularity the biggest increase was in business studies, up 23.6 percentage points to more than 125,000 entries. It now includes a business and communications systems option.
Religious studies entries were up 7.9 points and sciences generally were up a little - biology by four points.
MOST POPULAR GCSE SUBJECTS
Science: Double Award
Design and Technology
Modern languages continued the trend of recent years, declining overall but with an increase in the Spanish entry, up 3,340 this year to 61,323.
There was a general rise in achievement in the vocational qualifications, except in intermediate part one GNVQs.
There were new syllabuses in most GCSE subjects this year, designed to improve the qualifications.
But the convenor of the joint council, John Milner, said the results demonstrated that the standard of the exams had been maintained.
The Education Secretary, Charles Clarke, acknowledged it was a "tough challenge" to increase the proportions of young people achieving five or more top grades.
"I am confident that our secondary school reforms will help drive up standards even higher at GCSE in the future.
"I am encouraged by the progress in this year's 14 year old tests, where we have seen the best ever results."
But his Conservative shadow, Damian Green, said the gap between the best and worst students was widening and Labour was "failing to deliver".
More than 30,000 children left school with no qualifications.
Classical civilisation soared 10.7 percentage points in popularity
"Unless this damaging trend is reversed we will continue to allow generations to drift out of mainstream society and into crime."
The Liberal Democrat spokesman, Phil Willis, said the key question was how many children had English, maths, science and a modern foreign language.
One in four did not even make the attempt, and only 40% of those who did got good grades in all.
A common factor was alienation from the curriculum.
"Liberal Democrats believe that the age-related GCSE should be abolished and replaced by flexible national standard tests in core subjects."
The general secretary of the Secondary Heads Association, John Dunford, said further substantial improvements would depend on funding for smaller classes.
"With this year's funding problems, it's unlikely that schools will be able to turn around the rise in the number of ungraded results," he said.
In the longer term, he looked to Mike Tomlinson's review of 14 to 19 qualifications to propose stronger vocational options for those who did not succeed on traditional GCSE courses.