EDUCATION minister John O'Dowd said he is "very disappointed" after two English exam boards decided they will no longer offer GCSE courses in the north.
AQA and OCR made the decision after Mr O'Dowd said last year he would keep the A*-G grading system in Northern Ireland.
In September, pupils in England will be graded under a numerical system, with 9 the highest grade and 1 the lowest.
AQA and OCR said they will not operate two separate grading systems.
About a quarter of courses taken by pupils in Northern Ireland are through English and Welsh exam boards.
Mr O'Dowd said it was "very disappointing that some organisations are choosing to put commercial interests ahead of the needs of our young people".
"However, this response by some awarding organisations is not unforeseen," he said.
"I want to reassure pupils and parents that work is well underway to ensure that our young people can continue to access the widest possible range of subjects and courses, including those most relevant to the needs of our economy, to progress on their chosen path in learning or employment."
He said schools will be advised on new arrangements by the end of this month.
"In particular, CCEA will be able to advise on arrangements for those pupils who are already working towards qualifications in Maths and English Literature provided by these awarding bodies that have now decided to leave us," he said.
DUP assembly member Peter Weir said grades in the north should have changed in line with England.
"The situation we now have could have been easily resolved by adjustments to our grading system ensuring it was aligned with grades in England," he said.
