(ANSA) - BELGRADE, NOV 15 - Geoplin, Slovenia's largest energy trader, signed a natural gas supply agreement with Algerian energy giant Sonatrach on Tuesday, the Slovenian news agency STA reported. The agreement calls for the purchase of approximately 300 million cubic meters of natural gas per year for the next three years. Beginning January 1, 2023, the gas will be delivered through Italy. The deal will satisfy roughly a third of Slovenia's demand for gas from 2023. (ANSA).