Supplier Portal and OBN: Is there a way to view businesses who already particpate?

Summary:

We are trying to enable/encourage more of our suppliers to transact with us through Oracle Business Network (OBN) and/or Supplier Portal. We have many suppliers.

Is there a way we can see what business are already participants of OBN and Supplier Portal (even if they are not our suppliers)?

The background: We'd like to cross-reference (a) all business who participate in OBN/Supplier Portal already, with (b) our suppliers, to see if any of ours are already on OBN/Supplier Portal. If some of ours are already on there, it will make it easier for us to "onboard" them in our supplier enablement effort.