You're probably referring to this quotation, commonly attributed to Mussolini: "Fascism should more properly be called corporatism, since it is the merger of state and corporate power."

This is misleading; not only did Mussolini never say that, but the quotation in question is actually somewhat clumsily referring to the doctrine of corporat(iv)ism, which while obviously etymologically related to the word 'corporation' in its modern sense, bears very little in common with the sort of state-supported market capitalism that dominates in the US and much of the West.

Corporatism is actually much more influenced by the guild system and the policies of the Catholic church in the 19th and early 20th centuries, and was proposed as a 'third way' to correct the excesses of both capitalism and socialism.