There is no obvious meaning for "a power pack venture". The word "venture" often means a project that a company is doing (or a pair of companies are doing together).
It's only one phrase. I'm translating a document and the phrase is exactly like this. The way I understand it, these two companies are together and are potent in the undertaking business, is that right?
It sounds like A and B are jointly in a venture (business) that makes power packs (some sort of batteries).
(The undertaking business is about funerals (burying people in the ground).)