<p>A steel strip having a coating of an aluminium-zinc-silicon alloy on at least one surface of the strip is disclosed. The strip is characterised in that the aluminium-zinc-silicon alloy contains less than 1.2 wt.% silicon and also contains magnesium. A method of forming a coating of an aluminium-zinc-silicon alloy on a steel strip is also disclosed. The method includes moving steel strip upwardly through a coating pot containing a bath of an aluminium-zinc-silicon alloy and having an opening in a bottom wall of the pot and forming a coating of the alloy on the strip. The method is characterized by minimizing residence time of steel strip in contact with the aluminium-zinc-silicon alloy bath in the pot.</p>