Suncorp’s internal forecasts suggest a merger with the Bank of Queensland or Bendigo and Adelaide Bank would not be in the best interest of its shareholders and would likely produce limited synergies for the combined group.

Those calculations are expected to be at the centre of a final push from the company to convince the competition regulator to allow it to offload its banking division to ANZ in a deal that would deliver the Brisbane-based group’s investors a $4.1 billion cash windfall.