See this Finextra article. Pan-European payment processer Equens has won a five year deal to provide debit card processing services to Dutch banking group ABN Amro in support of the introduction of the single euro payments area (Sepa) in 2008. Papers in the Netherlands suggest that ABN AMRO achieved a significant price-reduction.
The news is in itself not stunning but had some more impact as an official of ABN AMRO outlined in the Financieele Dagblad that ABN AMRO would not pass on the benefits of cheaper processing to merchants but rather use those to try to prevent prices from rising in the future.