However, the Tory leader's proposal was immediately attacked by secondary heads who branded it elitist and outdated as the dispute about A-levels gathered pace.
Mr Hague's new grade would go to the top 2.5 per cent of candidates. He said it would help employers and universities to select high-flyers.
The controversial A* at GCSE was introduced by the previous government because of fears that the brightest pupils were not being stretched.
In a speech at Folkestone School for Girls, in Kent, Mr Hague said: "We believe that A-levels should be maintained as the gold standard in education and should be protected and strengthened. The new grade would ensure rigorous academic standards and spur young people on to the highest levels of achievement."
John Dunford, general secretary of the Secondary Heads Association, said: "This would make A-level even more elitist. We are looking for post-16 qualifications which will serve the whole population and not a small minority."
Under the Government's plans for A-level reform, from September next year pupils will be able to take five subjects in the first year of an A-level course to gain a new AS qualification. They will then decide whether to continue with three A-levels or carry on with more subjects.
The new courses will be in six modules chunks with exams that can be taken throughout the two years and mixed with vocational qualifications.
The National Association of Head Teachers warned the Government yesterday that its plans to reform A-level will fail. It wants a compulsory baccalaureate-style exam combining arts and sciences.
Under government plans pupils will be allowed to choose whether they take more subjects and universities will be free to keep their existing entrance requirements.
David Hart, the association's general secretary, told a conference yesterday that schools would be slow to take up new AS exams designed to broaden the sixth form curriculum.
He predicted that many universities would continue to select pupils on the basis of three A-levels and ignore the new exams.
Mr Hart accused the Government of dithering. "The danger is that lack of government enthusiasm will lead to nothing like the broadening necessary. This would be a tragedy, bearing in mind that the current system serves only a minority and provides little, if anything, by way of relevant programmes of study for the majority."
Independent school heads have already voiced fears that the new arrangements will dilute the "gold standard" of A-level and that universities will take no account of the new AS.
But Mr Dunford welcomed the changes. "The vast majority of schools will do AS levels though I think most will choose to offer four rather than five because of problems with resourcing and timetabling."
He suggested that universities might decide to make offers of places on the basis of pupils' AS results instead of relying on predicted grades.
There will also be new voluntary business skills tests to ensure that pupils leave school able to read spreadsheets, write reports and cope with maths, and tests in communications, computer technology and numeracy.Reuse content