MILAN- Italy's Enel has bumped up the size of a bond issuance programme set up in 2019 by its U.S. unit and linked it to sustainable development goals, the utility said on Tuesday.

In a statement, Europe's biggest utility said it had raised a $3 billion Commercial Paper Program to $5 billion.

The move is part of Enel’s sustainable finance strategy as it looks to have 48% of total group debt made up from sustainable finance sources in 2023 and more than 70% in 2030.

Sustainable-bond issuance surged to a record high in the first quarter as more countries and companies looked to tap growing demand from investors across the globe.

Environmental concerns have risen for many investors in recent years as the world steps up its transition to a low-carbon economy.

(Reporting by Stephen Jewkes; editing by Agnieszka Flak) ((stephen.jewkes@thomsonreuters.com; +39.0266129695; Reuters Messaging: stephen.jewkes.thomsonreuters.com@reuters.net))