Complex sentence: Letta is the secretary general of Agenzia di Ricerche e Legislazione (AREL), think tank founded by Beniamino Andreatta; he himself founded the associations "Trecentosessanta" and "VeDrò".
Split into simpler sentences: Letta is the secretary general of the think tank Agenzia di Ricerche e Legislazione (AREL), founded by Beniamino Andreatta. He himself founded the associations "Trecentosessanta" and "VeDrò".