Method for treatment of an exhaust stream, resulting from a combustion in a combustion engine, passing through an exhaust treatment system and comprising nitrogen oxides NO x, wherein said nitrogen oxides NO x comprise nitrogen monoxide NO and nitrogen dioxide NO 2; comprising - a first oxidation of compounds comprising one or more of nitrogen, carbon and hydrogen in said exhaust stream, wherein said first oxidation is carried out by a first oxidation catalyst arranged in said exhaust treatment system; - a determination of a value (NO 2_1 /NO x_1) det for a first ratio between a first amount of nitrogen dioxide NO 2_1 and a first amount of nitrogen oxides NO x_1, leaving said first oxidation catalyst; - a first supply of a first additive into said exhaust stream with the use of a first dosage device, arranged downstream of said first oxidation catalyst, wherein said first supply is controlled actively based on said determined value (NO 2_1 /NO x_1) det for said first ratio; - a first reduction of at least said first amount of nitrogen oxides NO x_1 via a catalytic reaction in a catalytic filter, arranged downstream of said first dosage device, wherein said catalytic filter consists of a particulate filter with an at least partly catalytic coating with reduction characteristics, which is arranged for catching and oxidising of soot particles, and to carry out said first reduction of said first amount of nitrogen oxides NO x_1, and wherein a catalytic reaction for said first reduction uses said first additive; wherein said active control of said first supply for said ratio depends on whether to achieve an effective soot oxidation in the catalytic filter or to achieve an effective reduction of nitrogen oxides in the catalytic filter; - a second supply of a second additive into said exhaust stream with the use of a second dosage device, arranged downstream of said catalytic filter; and - a second reduction of a second amount of nitrogen oxides NO x_2 reaching a reduction catalyst device, arranged downstream of said second dosage device, wherein said second reduction uses said first and/or second additive, and wherein said active control of said first supply is also based on a determined value (NO 2_2 /NO x_2) det for a second ratio, between a second amount of nitrogen dioxide NO 2_2 and a second amount of nitrogen oxides NO x_2, reaching said reduction catalyst device. - a first oxidation of compounds comprising one or more of nitrogen, carbon and hydrogen in said exhaust stream, wherein said first oxidation is carried out by a first oxidation catalyst arranged in said exhaust treatment system; - a determination of a value (NO 2_1 /NO x_1) det for a first ratio between a first amount of nitrogen dioxide NO 2_1 and a first amount of nitrogen oxides NO x_1, leaving said first oxidation catalyst; - a first supply of a first additive into said exhaust stream with the use of a first dosage device, arranged downstream of said first oxidation catalyst, wherein said first supply is controlled actively based on said determined value (NO 2_1 /NO x_1) det for said first ratio; - a first reduction of at least said first amount of nitrogen oxides NO x_1 via a catalytic reaction in a catalytic filter, arranged downstream of said first dosage device, wherein said catalytic filter consists of a particulate filter with an at least partly catalytic coating with reduction characteristics, which is arranged for catching and oxidising of soot particles, and to carry out said first reduction of said first amount of nitrogen oxides NO x_1, and wherein a catalytic reaction for said first reduction uses said first additive; wherein said active control of said first supply for said ratio depends on whether to achieve an effective soot oxidation in the catalytic filter or to achieve an effective reduction of nitrogen oxides in the catalytic filter; - a second supply of a second additive into said exhaust stream with the use of a second dosage device, arranged downstream of said catalytic filter; and - a second reduction of a second amount of nitrogen oxides NO x_2 reaching a reduction catalyst device, arranged downstream of said second dosage device,