decis repres govern member state european coal steel commun meet council april open tariff negoti articl xxiv gatt ecsc repres govern member state european coal steel commun meet council note commun commiss enlarg commun provis articl xxiv gener agreement tariff trade tariff concess hellen republ renegoti decid commiss request enter negoti articl xxiv gener agreement tariff trade respect product cover european coal steel commun commiss conduct negoti assist repres member state luxembourg april presid de kone