Exhaust treatment system , arranged for treatment of an exhaust stream , which results from a combustion in a combustion engine , comprising - a first dosage device , arranged to supply a first additive into said exhaust stream ; - a first reduction catalyst device , arranged downstream of said first dosage device , and arranged for reduction of nitrogen oxides NO x in said exhaust stream through the use of said first additive, wherein said first reduction catalyst device comprises at least one first multifunctional slip catalyst (SC 1 ), said at least one first multifunctional slip catalyst (SC 1 ) including: - a nitrogen oxides NO x reducing coating being in direct contact with the exhaust stream that passes through the exhaust treatment system ; and - one or several substances comprised in platinum group metals, and/or one or several other substances that provide similar characteristics as for the platinum group metals; said at least one first multifunctional slip catalyst (SC 1 ) thereby being arranged primarily for reduction of nitrogen oxides NO x , and secondarily for oxidation of additive in said exhaust stream ; - a particulate filter , at least partly comprising a catalytically oxidising coating, which is arranged downstream of said first reduction catalyst device , and is arranged to catch and oxidise soot particles, and to oxidise one or several of nitrogen oxide NO and incompletely oxidised carbon compounds in said exhaust stream ; - a second dosage device , arranged downstream of said particulate filter , and arranged to supply a second additive into said exhaust stream ; and - a second reduction catalyst device , arranged downstream of said second dosage device , and arranged for reduction of nitrogen oxides NO x in said exhaust stream through the use of at least one of said first and said second additive. - a first dosage device , arranged to supply a first additive into said exhaust stream ; - a first reduction catalyst device , arranged downstream of said first dosage device , and arranged for reduction of nitrogen oxides NO x in said exhaust stream through the use of said first additive, wherein said first reduction catalyst device comprises at least one first multifunctional slip catalyst (SC 1 ), said at least one first multifunctional slip catalyst (SC 1 ) including: - a nitrogen oxides NO x reducing coating being in direct contact with the exhaust stream that passes through the exhaust treatment system ; and - one or several substances comprised in platinum group metals, and/or one or several other substances that provide similar characteristics as for the platinum group metals; - a nitrogen oxides NO x reducing coating being in direct contact with the exhaust stream that passes through the exhaust treatment system ; and - one or several substances comprised in platinum group metals, and/or one or several other substances that provide similar characteristics as for the platinum group metals; - a particulate filter , at least partly comprising a catalytically oxidising coating, which is arranged downstream of said first reduction catalyst device , and is arranged to catch and oxidise soot particles, and to oxidise one or several of nitrogen oxide NO and incompletely oxidised carbon compounds in said exhaust stream ; - a second dosage device , arranged downstream of said particulate filter , and arranged to supply a second additive into said exhaust stream ; and - a second reduction catalyst device , arranged downstream of said second dosage device , and arranged for reduction of nitrogen oxides NO x in said exhaust stream through the use of at least one of said first and said second additive. <EOS>