MIAMI--(BUSINESS WIRE)--ACI Worldwide (NASDAQ: ACIW), a global leader in mission-critical, real- time payments software, today announced a collaboration with RYVYL EU, a leading payments service provider (PSP) and acquirer in Central Eastern Europe (CEE), to help merchants across the region increase revenues through higher transaction conversion rates. RYVYL EU is an EU-regulated electronic money institution based in Sofia, Bulgaria, and is a wholly owned subsidiary of RYVYL Inc. (NASDAQ: RVYL). Its service ...