The research shows that even nine years after the 2006 cohort began their studies, only 73.5 per cent of students had completed a course.

The figures come as spiralling taxpayer-funded student loans look set to blow out to $11.1 billion a year by 2026, or 46.3 per cent of the nation's public debt, according to figures from the Parliamentary Budget Office.

In Sydney, Western Sydney University had the lowest completion rate after only 73.7 per cent of the university's 2006 intake completed their degrees.

Macquarie had the next lowest graduation rate of 77 per cent, while the University of Sydney had the highest completion rate after 88 per cent received their degrees within nine years.

The figures are to be released in a report by the federal Department of Education on Wednesday, the same day 44,190 NSW students receive notices offering them university places this year.

Federal Education Minister Simon Birmingham warned students to "know exactly what they're signing up for".

"We've heard too many stories about students who have changed courses, dropped out because they made the wrong choices about what to study, students who didn't realise there were other entry pathways or who started a course with next to no idea," he said.

"To the thousands of students anxiously checking emails, text messages, newspapers and mailboxes this week to learn what your future study options might be, I urge you to take your time to understand those options."

Regional NSW universities, including the University of New England, Southern Cross and Charles Sturt, performed the worst of the state's universities after only 60 per cent of students completed their degrees over a nine-year period.

The department restricted its cohort analysis to nine years because students who didn't complete a course over that period were unlikely ever to do so.

A spokesman for Western Sydney University said the university was aware its students could take longer to complete their degree due to a higher number of part-time students, a higher percentage of mature-age students and students who participated in higher levels of paid employment while studying.

The vice-chancellor of the University of Sydney Michael Spence said the university was very "proud of its strong retention rates," while UNSW's deputy vice-chancellor of education Merlin Crossley said the university was pleased to see the continuing focus on completion rates.

"It is good that our rates are strong and there is evidence they continue to rise," he said. 

The department also found the three most significant factors that led to students dropping out.

Part-time students were less likely to complete their studies, mature-age candidates had a higher chance of pulling out and students with lower ATAR scores were less likely to graduate, the department concluded.

Last year, a Fairfax Media investigation found that up to 60 per cent of students were being let into NSW universities below the advertised minimum ATAR cut-off, leading to concerns over education standards, mounting student debt and anger from students who never applied for courses for which they would have been eligible.

From next year, universities will be forced to publish the minimum, median and maximum ATARs of students who have been admitted to a course among a host of other quality assurance measures, following recommendations from the federal government's Higher Education Standards Panel.

The Group of Eight universities will publish this information this year.

The University Admissions Centre's spokeswoman Kim Paino said the UAC and universities would work closely this year to provide additional information to students.

"We welcome Mr Birmingham's acceptance of the transparency recommendations from the Higher Education Standards Panel," she said.

The main round of university offers are to be released online on Wednesday from 6pm.

Join us for the live blog at smh.com.au.