“Interregional cooperation across the entire EU territory and neighbouring countries on topics closely related to regional development.”

INTERREG III is a European Community programme designed to strengthen economic and social cohesion in the European Union through the cooperation of partners throughout Europe. 
INTERREG III has three emphases:

Cross-border cooperation (INTERREG IIIA)
Transnational cooperation (INTERREG IIIB)
Interregional cooperation (INTERREG IIIC)

The area of the European Union is divided into four INTERREG III areas: North, South, West and East.

www.interreg3c.net