The agreement was signed to improve the environmental situation and preserve biological diversity in the Adriatic, and the three countries will cooperate on the sustainable development of this sea, the Croatian state secretary for environmental protection, Nikola Ruzinski, said after the signing.
The agreement was also signed by Slovenia's Environment Minister Janez Podobnik and Italian Ambassador to Ljubljana Daniele Verga.
Podobnik said he expected the other countries in the Adriatic basin also to sign the agreement.
The agreement was signed during a conference of countries signatories to the Barcelona Convention on the Protection of the Mediterranean, which began on Tuesday and ends on Friday.