The Commerce Commission is still weighing up whether to allow banks and major retailers to negotiate as a group with Armourguard, the country's only cash transit service

It's declined an interim authorisation, while it continues to mull over whether to allow full authorisation.

The Banking Association wants a collective ten-year deal, so services remain viable and reliable for banks dealing with an ever-dwindling amount of cash.

But Armourguard claims the deal could drive down what it says are already unsustainably low prices.

It wants fees set by an independent third party, with banks paying most of the cost of cash distribution.