"Corporatocracy is a term used to suggest an economic and political system controlled by corporations or corporate interests." http://en.wikipedia.org/wiki/Corporatocracy
I'd accept that, though the more proper term, economically, I think, is corporatism.
"Fascism should more appropriately be called corporatism because it is the merger of state and corporate power." - Benito Mussolini -- from Corporatocracy, Corporatism, Fascism.
Or the even older term, mercantilism.
The question is how did this happen? Is it the greed for wealth of big business or the greed for power of the government? A combination, but which is the sufficient cause and which the necessary?