Amalgamation

The basic concept of amalgamation means combination or collection. In a way, it's a synonym for merger, though it has a slightly broader connotation, hinting at a wider process rather than a single deal to combine two companies.

This subtilty might make sense with a quick example. In business discourse, amalgamation is something that Standard Oil did in the Robber Baron days, whereas a merger is something that Sprint and T-Mobile are doing today.