ACCRA, June 19 (Reuters) - Heads of state of the Economic Community of West African States (ECOWAS) have adopted a new road map to launch a single currency for the 15-member bloc in 2027, the president of the ECOWAS Commission Jean-Claude Kassi Brou said on Saturday. (Reporting by Christian Akorlie Writing by Bate Felix Editing by Mark Potter) Our Standards: The Thomson Reuters Trust Principles.