Corporations

So I was playing sins a few days ago, and after I came to late-game, I realized that after you get all the research stations and technologies, and in a big game take over your system there is nothing left economical except for building more trade ports at other planets. After a certain point the expansion part of the game quietly slips away from your priorities. You have all the resources you need, and there is no more expansion to new planets, or even change in your own planets.

Now on to the real point.
In our world today, we see that corp. and companies are launching satellites into space, not just the government. In this late period, would it be any different? There eventually would be a point where the nation would have to take total control of space, but could there not be the chance for independent organizations within the nation to grow? This Idea might coincide with the automation options available with ships, except it would apply to planets and stations. This idea might kindav be like Sim-City, but what if you could rent out sectors of space, of a big enough size so it would hamper you to be fair, but that could be purchased by a Organization, which would kindav be like a mini-faction. In Sim-City, you put down squares for buildings, and then independent sources take control of them. This would enable more use of the space, because honestly in my major planets in my deep "safe" zones.

These corporations could maybe build shipyards using the space provided, or even independent trade ports, which would have some kindav bonus for them if you are trading with them. I really dont see how else they could be affected, but any ideas on this concept?