Hi Karthika--
Actually, we would set up a single Supplier account for your company on the Network. Any Catalog Managers that would need to upload Catalogs would have a login (there is an Admin function on Ariba Network accounts that allow you to manage Users).
Because this Network account would exist for your company to manage Catalogs and route orders—to your own company, the Network fees would be waived.
I hope that helps to explain it.
Mark Davis
Ariba Catalog Team