A major OECD report, published on the 28 January, ranked NI students 22nd out of 23 countries in literacy and 21st out of 23 in numeracy.
However, the OECD now say that they initially published the wrong data, and NI students are "in reality closer to mid-table of the surveyed countries".
The OECD say the mistake in the Building Skills for All report was only identified and corrected during Monday 1 February.
The new data shows that Northern Irish students rank 13 out of 23 for literacy skills, and 14 out of 23 for numeracy skills.
Northern Ireland students now rank above those in countries like the Republic of Ireland, Spain, England, the USA and Canada for reading and writing skills.
Meanwhile, Northern Ireland students rank better than those in countries like Australia, Poland, the Republic of Ireland, England and the USA for maths skills.
The OECD mistake affected rankings on the skills of university students published on pages 15 and 53 of the report.
In a statement to the BBC, an OECD spokesperson said a formatting error was to blame.
"In the course of formatting the document for publication, the graphic image for figure 3.2 (but not the title) was mistakenly replaced by the graphic image for figure 2.3," the spokesperson said.
"So while England's position changed little, Northern Ireland is, in reality, closer to mid-table of the surveyed countries."
The position of a number of other countries in the rankings was also affected and has been changed.
Finland is now the highest ranked country in the world for students literacy skills, instead of Japan.
Belgium is now the highest ranked for students' numeracy skills, instead of Finland.
The OECD say the rest of the data published in the original report is accurate.
The Organisation for Economic Co-operation and Development (OECD) has apologised for publishing the wrong information about the reading, writing and maths skills of Northern Ireland university students.