A credit union service organization—Co-op Solutions—is offering its clients membership in the newly formed Co-op Pay Network, a program designed to lower network fees that credit unions pay and optimize the interchange fees they earn on debit card transactions made at both POS terminals and ATMs. The new network will not create a consumer-facing brand, so no cards will have to be reissued. It will operate on the Fiserv-owned Star Network, which provides access to more than one million POS and ATM locations in the US. Credit unions could choose to drop the Star logo from their cards. Co-op...