Education Secretary Michael Gove is preparing a major shake-up of A-Levels as the latest stage of exam reforms.
Officials have been developing an Advanced Baccalaureate that would include a mix of A-Level subjects, a 5,000 word essay and voluntary work, according to The Times.
He also is expected to scrap modular courses in favour of a two-year versions with exams at the end.
AS-Levels would be retained, but kept separate from the new 'A-Baccs'.
Anthony Seldon, headmaster at Wellington College, said the announcement is "long overdue".
"Michael Gove's recognition that the A-level system needs an overhaul is long overdue and to be greatly welcomed.
"I am strongly supportive of his thinking, as it will render A levels even more like the best exam system in the world, which is the International Baccalaureate Diploma, offering a final exam at 18 with no modules over two years.
"The best announcement any government could make would be to adopt the IB Diploma, so I would encourage Michael Gove to go further still towards considering this gold standard system."
Details of the plans emerged after Gove unveiled proposals to ditch GCSEs in core subjects, replacing them with tougher exams each overseen by a single awarding body.
Under the new A-Baccs, students could be obliged to select "contrasting" subjects, to counter criticism that there is currently too much specialisation at age 16.
One option apparently being considered is to limit the A-Bacc to teenagers who choose at least two "traditional" A-Levels from a list generated by top universities.
A Department for Education spokesman said: "A-Levels will not be replaced under any circumstances.
"There are public consultations about reforming A and AS levels.
"There are also numerous suggestions about new A-Bacc league table measures but no decisions have been made."
Shadow education secretary Stephen Twigg said: "We support the concept of an A Bacc, however Labour would ensure it includes a broad range of subjects and sits alongside our proposed Tech Bacc for vocational courses. If these changes include community work, an extended project and a wider range of courses, then that is welcome.
"Unfortunately, Michael Gove seems to be ignoring important subjects like computing and engineering which are critical for the modern economy.
"The Government must address the big challenges to ensure a One Nation education system - ensuring a gold standard route for vocational education and every pupil studying English and Maths until the age of 18."