The government sparked a market rout last month with the surprise announcement of a 40% tax on the profits banks are reaping from rising interest rates.
The option would benefit banks that hold a higher proportion of Italian government bonds among their assets relative to loans.
Banca Akros and broker Equita also expect most banks to pay the tax.
Equita also said paying the levy would allow lenders to maintain more flexibility over their remuneration policy.
Switching the tax basis to risk-weighted assets helps banks which have a lower 'risk density', meaning the average risk weight per unit of exposure.
Persons:
Jennifer Lorenzini, Equita, Akros, Siena, Valentina Za, Kirsten Donovan
Organizations:
REUTERS, Generale, Banca Akros, ICCREA, Bank, Banca Generali, Thomson
Locations:
Monte dei, Siena, Italy, Italy's