The defined pension benefit payments are a heavy burden on the banks, and pension fund shortfalls were earlier topped up with public money.
Pension rights for new recruits were scrapped as part of a government drive to rescue state banks, which paved the way for these entities to be recapitalized in 1997.
The Ceylon Bank Employees Union has now taken up the issue with the Strategic Enterprise Management Agency (SEMA) a unit that overlooks restructuring of key state ventures.
The Ceylon Bank Employees Union President M R Shah says initial talks with SEMA officials were very positive.
Unions are threatening to strike, if pension rights are not restored to state banks.
In 1993, nearly 7.5 billion rupees of public money was used to top up pension funds of state banks.
The People's Bank pension fund got 3.2 billion