OPEC 's mandate is to `` coordinate and unify the petroleum policies '' of its members and to `` ensure the stabilization of oil markets in order to secure an efficient , economic and regular supply of petroleum to consumers , a steady income to producers , and a fair return on capital for those investing in the petroleum industry . ''
Its work is to `` coordinate and unify the petroleum policies '' of its members . Also to `` ensure the stabilization of oil markets in order to secure an efficient , economic and regular supply of petroleum to consumers , a steady income to producers , and a fair return on capital for those investing in the petroleum industry '' .