Swiss International Airlines - Delay Compensation on Swiss?

Friday nights' last flight from GVA to LCY was cancelled, I was rebooked to LCY on the following day via ZRH resulting in a 12 hour delay arriving in London. Hotel & transfers were arranged by very helpful LX staff though (naturally) no advice was given whether I would be able to claim compensation under EU law.
Question is whom I can contact to claim any compensation? I know that in Germany one can contact the "Luftfahrt-Bundesamt" - would I need to write to the Swiss equivalent, and if so, would anyone have details? Or contact the airline directly?
Thanks!!!

Do you know what the cause for the cancellation was? That will decide whether the airline has to provide you "compensation" vs. just "care", which they did.

You will first have to contact the airline to make your claim. Only if they don't cooperate can you go through the Swiss enforcer, the BAZL (http://www.bazl.admin.ch/dienstleistungen/passagierrechte/index.html?lang=en).

The reason for the delay was an earlier technical problem with the aircraft which delayed the incoming flight. By the time it got to Geneva it was too late to go to LCY as City Airport closes early. I'll write to Swiss and keep my fingers crossed.
Thanks for the quick reply!

Good luck & please keep us updated on the outcome.

I tried claiming compensation from Swiss in a similar scenario in the spring and they did their very best to get out of it.