This report examines and compares the lobbying routes taken by Swedish and Norwegian energy-intensive industry firms during the revision of the European Emissions Trading System. Two key explanatory factors are in focus here - whether the company has its origin in the EU member state Sweden or in non-member Norway; and the size of the company. Six companies are chosen as cases: Norsk Hydro, Norcem and Norske Skog from Norway; and SSAB, Cementa and Svenska Cellulosa Aktiebolaget from Sweden. A key finding is the extensive use of European associations by all these firms in lobbying EU institutions. Also prevalent is the use of national associations, which would indicate benefits in the form of better institutional response to collective lobbying and resource-sharing aspects. Although Norwegian firms seem to have struggled more than Swedish firms when it comes to lobbying EU institutions, due to lack of access to the EU, not all differences can be explained by the fact of originating in an EU member state Sweden or non-member Norway. While company size has a positive effect on the number of available lobbying routes, this appears to depend on cross-border production and possibly other influences as well.