A survey of the latest salary data has revealed that academics in new universities earn on average Pounds 3,500 less than their counterparts in older ones.
According to the Association of University and College Lecturers, which carried out the analysis, only a pay rise substantially above inflation plus the establishment of a pay review body would restore salaries to competitive levels.
The average salary for a new university academic is currently Pounds 25,323. This year the two sectors will negotiate pay simultaneously for the first time.
The AUCL highlighted the differences in its salary policy paper published this week. Almost half (48 per cent) of lecturers in old universities were said to hold promoted posts as either senior lecturer, reader or professor, compared to 20 per cent in the new universities.
The union argues that lecturers, researchers and other academic-related staff in the new universities would benefit greatly from transfer to old university pay scales even though the latter "lag well behind comparable professions".
But the AUCL adds that the prospect of unified negotiations covering the whole higher education system remains distant.
Meanwhile, 2,000 further education lecturers in Northern Ireland will receive a pay rise of 2.7 per cent denied to them last year, plus a lump sum of Pounds 1,000 to move over to new contracts following a year of negotiations.
College lecturers' union Natfhe said lecturers and senior managers in 17 colleges voted by 733 to 0 to accept the new contract, which comes into effect in September.
The union said college employers in Northern Ireland had originally pushed for a "draconian" new contract. The agreement finally struck between Natfhe and the employers retains contractual safeguards on teaching hours and introduces new protection against excessive workloads.