Are you referring to Gramm-Leach-Bliley here? As far as I can tell, it basically only served to remove barriers previously imposed, i.e., reduce government intervention. On the face of it, that's pretty libertarian - I don't recall many libertarians arguing that government should actively intervene to prevent consolidation, so removing that intervention seems like a move in the direction of libertarianism.
So I suppose you must be arguing that passing that act was not libertarian because of other regulations that still exist, thus making it "corporatist" rather than "libertarian"? But then you kind of get into the issue that few things if any would constitute moves toward libertarianism, because in the current business climate, whatever the cause, big business holds a tremendous amount of power, and just about any de-regulation would allow them to exercise more of that power.
It seems to me then that it would be hard to make a more libertarian society, by this line of reasoning, with anything short of some kind of "revolution from above" to even out the playing field, but that in itself would be pretty un-libertarian.
Whatever that analysis brings, as far as I can tell, the GLBA was passed based on the belief that it would increase competition and "modernize" finance by removing government barriers.
