In addition to his committee assignments, Duin served as deputy chairman of the German-British Parliamentary Friendship Group from 2010 until 2012.

Together with Doris Ahnen, Bärbel Diekmann, Barbara Ludwig and Heiko Maas, Duin co-chaired the SPD's 2009 national convention in Dresden.

[1] Duin resigned as Member of the Bundestag on 21 June 2012 and was appointed Minister for Economics, Energy, Industry and Commerce of the state of North Rhine-Westphalia in the government of Minister-President Hannelore Kraft on the same day.

In the negotiations to form a Grand Coalition following the 2013 federal elections, Duin was part of the SPD delegation in the working group on economic policy, led by Ilse Aigner and Hubertus Heil.

During his time in office, Duin was a member of the German-Russian Friendship Group set up by the German Bundesrat and the Russian Federation Council.