A new code of practice is to be introduced to ensure that an A grade means the same thing under different exam boards. The future of AS-levels - equivalent to half an A-level - is to be reviewed.
The Secretary of State also called on examination boards to improve consistency in spelling, punctuation and grammar.
Mr Patten's announcement, made at a meeting organised by Conservatives in Worcester, seemed designed to pre-empt a report due for release on Monday which will call for the abolition of A-levels. The National Commission on Education will say that they should be replaced by a broad-based yet 'rigorous' exam which would encompass several subjects.
Mr Patten said: 'GCE A-levels are here to stay. They have been a remarkable educational success story and a hallmark for quality and excellence.
'Throughout the post-war period, each time we have wantonly destroyed a tried and tested feature of our education system, we have usually come to regret it. We must not allow A-levels to go the same way. They have stood the test of time. They must be preserved - and indeed strengthened - while at the same time providing high-quality alternatives,' he said.
His announcement follows concern that standards may have been allowed to slip. The proportion of students who gain the top grade at A-level has doubled over the last 20 years to nearly 14 per cent and there are wide variations in the percentages gaining top grades under different boards.
Mr Patten believes that a way had to be found to reward students of exceptional ability. Until recently, the most able pupils used to sit special papers, or S-levels, alongside their A-levels, but these have all but died out in recent years.
He added that the Government would also be promoting new General National Vocational Qualifications in addition to the International Baccalaureate, which combinines both academic and vocational training.
Nigel de Gruchy, general secretary of the National Association of Schoolmasters Union of Women Teachers, criticised Mr Patten's announcement that A-levels would remain unchanged. The exams could be reformed to bring in a wider range of subjects, he said.
'By proceeding on two separate kinds of A-levels you are bound to demote the vocational to second-class status. That flies in the face of what Mr Major said he wanted, which was parity of esteem,' he said.
The National Commission on Education will say that A- levels force teenagers to specialise too early, according to a report in yesterday's Daily Mirror. A baccalaureate like the one taken by French children would be more suitable, it will add.
The commission's report is also expected to recommend that children should start school at the age of three. It wants the private sector to provide more higher education funding so that state money can be devoted to the early years of schooling.
The commission was set up nearly three years ago by the social policy academic Sir Claus Moser, Master of Wadham College, Oxford, to consider all aspects of education after the Government turned down his call for a Royal Commission on education.Reuse content