Is this a run-on sentence?
In an effort to deter counterfeiters, the central bank of Norway wanted to redesign the nation's currency and sponsored a competition to find a fresh look for the banknotes.

 - no
 - yes
This is not a run-on sentence. It is not formed from two sentences that have been run together without appropriate punctuation.
In an effort to deter counterfeiters, the central bank of Norway wanted to redesign the nation's currency and sponsored a competition to find a fresh look for the banknotes.