Will passengers/cargo transfer in this situation?

Hi I hope someone can answer this question for me:

I am thinking of starting a subsidiary for handleing cargo (Company C). Let's say my holding (Company A) has Interline agreement with Company B (Interline), will passengers and cargo be transferred from Company B (Holding's Interline partner) to Company C (new subsidiary) through my holding company as like a middle man? Of course, my subidiary will have Interline with my holding company. Or does the new subsidiary needs to have Interline with Company B in order for any transfers to take place?

Thanks for your response.

As I understand the IL concept of this game, in this case Company C needs to have an IL agreement with Company B. Otherwise you could just connect to one single company with more than 100 IL's!

B and C need an Interlining contract. Otherwise they won't connect.

OK. Thanks