What firms or corporations that have made the decision, or considered an opportunity to split up the larger company? Note: This is not a stock split, but a decision to split a corporation into different entities.

Describe the type of market(s) the companies operate in (competitive, oligopoly, monopoly). Who would likely be impacted by the split? What are the reasons that the executives would split the company up using the concepts such as: cost-minimization rule, production and cost theory, the conditions that make a market competitive, long-run adjustments to maximize profit, ... etc...

Cite your reference.