Hi
I’m was supposed to fly in 17 JUL from BLL via AMS and LIN to BRI with an ETA of 14:20. The last leg is operated by ITA but with a KL flight number. Ticket is also booked at KLM.
Today I saw that our last leg (LIN-BRI) got canceled and the new itinerary had a 12 hour layover on LIN with arrival in BRI at 23:10.
I called the PSL and options were very limited. Everything is fully booked. They offered me a BLL-AMs-FCO-BRI route now with ETA 22:55 in BRI but not such lengthy layover so it’s more bearable.
KLM never informed me, I just saw it by coincidence in the app. The agent told me the reason of the cancellation was technical.

question is: am I entitled to EU 261 compensation and if so, for how much per pax on this trip?

Unfortunately, it is all too common that with codeshares the notification chain breaks down...

Re. compensation.
Yes, you are eligible (unless they can prove unavoidable reason for cancellation), for 400 EUR (Type 2 flight), from ITA.

On 17 July there is a 4-hour strike of Italian air traffic controllers, from 14:00 to 18:00. This must be the reason for the cancellation. Not being ITA's fault, I doubt EU261 compensation would apply.

If that is indeed the reason, then no compensation is due.

agent said it was a technical cause.

Hi

I got an answer from KL and they are claiming they aren’t supposed to compensate as it was the ITA flight was canceled and I have to request compensation there, not KLM.
But my whole trip got rebooked, so all involved flights were changed from BLL-AMS-LIN-BRI to BLL-AMS-FCO-BRI.
Is it true what KL is claiming?

Yes. ITA's cancellation is what caused the problem.

But given that there apparently was an ATC strike in Italy that day (see post 3), your chances of success with ITA appear slim. They cannot operate flights when there is no ATC.