Exam boards will give universities all 18 grades that make up an average three A-levels to help them select students. A-levels are split into six modules.
More than 20 per cent of scripts are awarded an A grade, which universities say makes it difficult to identify the brightest candidates. As each A-level consists of six modules, it means students will be offered provisional places on the most popular courses only if they clock up 18 grade As.
The scheme, revealed by Ellie Johnson Searle, chief executive of the Joint Council for General Qualifications, the body representing all exam boards, will be piloted next year, and implemented if successful. Teachers' leaders said it would put sixth-formers under more pressure to get A grades for each module.
The scheme emerges just a week before this year's A-level results are announced.
They are expected to show a further rise in the number of candidates gaining A-grade passes. For several years, universities have said that the number of students getting A grades at A-levels made it impossible to select the best candidates for sought-after courses such as law and medicine.
Applicants with three grade A passes were routinely turned down for courses at universities such as Oxford and Cambridge - without tutors knowing whether they scored higher marks than those accepted. The two universities turn away about 5,000 candidates with three A-grade passes a year. This year's results are likely to mean the admissions tutors had even more difficulty in identifying the cream of the crop. But Dr Johnson Searle says only 6 per cent of candidates who gain three A-grade passes at subject level also get A grades in each module. That brings the number with the best marks more into line with the demands of top universities' most popular courses.
Oxford and Cambridge say they want to select from the top 5 per cent for subjects such as law and medicine.
Dr Johnson Searle said: "We've got the information and there's no reason why they shouldn't have it."
The scheme will remove the need to introduce a new A* and A** grade at A-level suggested by Sir Mike Tomlinson, the former chief schools inspector. Although ministers were once attracted to the idea, it found no favour in the education world where it was thought it would devalue the A grade.
Dr Johnson Searle said the new plan would avoid the need to pass on students' individual marks to universities. The plan emerged after talks with the Universities and Colleges Admissions Service.
David Hart, general secretary of the National Association of Head Teachers, said the decision was "as inevitable as night follows day". "I think they're just being realistic. There is enormous pressure from the universities for more information. There is immense competition for the most popular courses. I think it is a better solution than creating an A* or A** grade." He said it emphasised the need for reform of what was ''a creaking system''.
For the new scheme to be successful, it will be necessary for universities admissions staff to change their policy on offering provisional places. To ensure they select the brightest candidates, they will have to insist on grade-A passes in all modules.
n Half of this year's potential undergraduates say they would be less likely to go to university if they were making their decision next year when top-up fees will be introduced, a survey reveals.
Selecting the best
* Introducing new A* and A** grade. Recommended by former chief schools inspector Sir Mike Tomlinson and initially favoured by Downing Street, it was opposed by the education world because it was felt it would devalue the A grade.
* Allowing only a certain percentage to obtain A-grade passes each year. An idea backed by the Conservatives in the election campaign.
* Giving universities the grades for each A-level module. It would supply the necessary information to universities to help them make decisions.
* Giving students' marks to universities. There is nothing to stop admissions tutors asking for them now - although it does not happen. It is a similar solution to passing on the module grades but would not show if students had a weakness in a particular area.