Commonwealth Bank has re-joined talks with the three other major banks on a proposal to establish a shared ATM network across Australia.Several banking industry sources confirm that the country's largest bank, which operates more than 3000 automated tellers, is once again participating in the discussions after bailing out of negotiations in 2018.The banks are looking to reduce the cost of operating their ATM fleets as digital forms of payment erode consumer demand for cash.The decline of cash as a mode of payment has undermined the business case for banks continuing to manage their proprietary ATM networks.While NAB, Westpac and ANZ are committed to pooling their fleets under a utility company to be managed by an external operator, CBA remains sceptical as to whether it would benefit from participating in such a venture.In 2018 the three other majors withdrew thousands of ATMs from service as CBA continued to increase the size of its fleet.One of CBA's big concerns is that it would be forced to stump up more capital than the other banks to fund upgrades to a merged network because of its bigger customer base.For the planned utility model to work, the banks will need to replace aging machines with new generation "recycler" ATMs that are able to dispense notes deposited by customers.The recyclers are likely to improve the economics of managing ATM fleets because they hold more notes and extend the average times for machines to be replenished manually.Westpac's former chief executive Brian Hartzer recently sold around one third of the bank's ATM network to cash logistics provider, Prosegur.At the bank's full year profit announcement last month Hartzer said that he hoped the sale would be a precursor to the formation of a utility solution for the industry.Rumours have circulated in banking circles in the last week that CBA has been trying to offload its non-branch ATMs to Prosegur, but a CBA spokesman yesterday dispelled the conjecture.Prosegur is among a raft of cash logistics firms angling to secure the right to manage a unified network. Others vying for the contract include Armaguard, Next Payments and Cardtronics.A source familiar with the utility talks at one of the Melbourne-based banks told Banking Day he was hopeful CBA would join the proposed utility.However, the source said that if agreement could not be reached the other three banks were prepared to pool their fleets without CBA's involvement.Meanwhile, NAB has appointed veteran banking executive David Banks as its new head of ATMs following a restructure of the business area.Banking Day understands that Rebecca Kotow, who has held the role for the past two years, will depart the bank at the end of the week.Banks also will replace Kotow as NAB's representative on several industry bodies, including the Australian-based ATM Forum and the US-based ATM Industry Association.Kotow was a leading figure in initial moves by the major banks to set up an ATM utility in 2017.However, the business case for a utility model advanced by NAB and ANZ at the time disintegrated when CBA decided