unite? merge? amalgamate? join?

[Imola]

Hello,
What is the right word when two banks turn into one? Are there different words for these situations:
1. a bigger one buys a smaller
2. two "equal" banks becomes a third one?
Thanks for your help.

[Belles1654]

I only know "merger" so I would say they merged. But I could see a news report talking about two companies uniting "for" or "against" something. Or even two companies have united (of equal strength and size) to form something else a "third" thing. This is my take on it. I hope it helps. -Belles