HELSINKI (Reuters) -Finland has agreed a 10-year charter for a floating storage and regasification (FSRU) vessel with U.S. based Excelerate Energy to help replace Russian gas supply, finance minister Annika Saarikko said on Friday. “The LNG terminal will make it possible for us to break free from Russian gas,” Saarikko said in a statement. The announcement coincided with Finland’s state-owned energy group Gasum saying Russia’s Gazprom Export had informed it that natural gas supplies from Russia to Finland would be cut on Saturday 21 May at 04.00 GMT. Last Friday, Finland’s emergency preparedne…