The automatic teller machine sector could receive a fresh dose of funding - and one likely to drive further consolidation of independent providers - with a possible takeover bid for ASX-listed Customers Limited.Customers confirmed yesterday that it "held discussions with a potential purchaser" after the ASX queried the rise in the share price from less than 80 cents in late September to $1.10 at the end of last week.The Australian Financial Review reported speculation of a private equity bid back in May.If Customers Limited does change hands it will be the fourth time since the founding of the business - originally known as ATM Solutions - in the late 1990s.Bank of Queensland, Macquarie Bank both bought the firm and sold it on after only a few years. Customers (then a micro cap under different management) bought Customers in 2007.The managing director and founder of the business, Tim Wildash, remains with the firm and would presumably do so under a further change of ownership.The business vision remains the same: to roll up the small operators in the ATM space and earn a steady yield by providing access to cash in locations not served by banks. The introduction of direct charging at ATMs by the ATM owners has, in theory, improved the viability of the business model, though, in some cases, ATM owners share a high percentage of this fee with the merchant, so curtailing profits.Customers operates around 5700 ATMs in Australia, accounting for around 22 per cent of the market as measured by ATM numbers. The firm operates the largest ATM fleet in Australia, though ATM numbers are in decline across the industry. The Australian Payments Clearing Association puts the number of ATMs at 25,950 at June 2011, down from 28,760 a year earlier.While Customers is a steady buyer of niche fleets of ATMs (and yesterday said it was in talks to buy yet another), smaller operators continue to spring up.And while the potential bid for Customers must exceed the present market capitalisation of A$155 million, other ASX-listed owners of ATM fleets have recently reduced the carrying value of these assets in their financial statements.MyATM, iCash Payments and GRG International all reduced the value of their ATM investments in their June 2011 financial statements.Customers reported subdued earnings for the June 2011 half, with a net profit of A$7.2 million in the June 2011 half, down from $11.6 million in the December half. Earnings before interest and tax fell one fifth to $9.6 million in the half. EBITDA fell five per cent, while revenue fell two per cent, to $62 million.