American Express is confident it can maintain its premium level of merchant fees, even as "network" or co-branding becomes more important.Steve Squeri, president of global corporate services for Amex told an industry conference that "I think, when you [analysts] think about [network sales agreements], you are cannibalising yourself."Australia has been an early market for Amex's efforts to market credit cards in conjunction with ANZ, Commonwealth Bank and Westpac.It also has a co-brand arrangement in place with David Jones, where Amex is no longer obliged to underwrite the profit share for its partner."And the reality is, no, and historically what has happened, and I can cite Singapore, I can cite Australia, [where] we have had GNS opportunities, we have actually increased our market share, and the same thing has happened in the UK as well."The GNS channel allows us to get to card members that we wouldn't get to [for example]. They just have a very high affinity with their banking institution. "If you look at what has happened in Australia over time, there was some discount rate pressure… but it's a corridor of value, there is only so much differentiation that you can have. "So, probably over time, there will be some pressure, but we have been available at a premium discount rate in Australia."Squeri was speaking at the Barclays Global Financial Services Conference on Wednesday night. His comments were reported in full by Seeking Alpha.