Same Account records to different Business Units - who is the Owner?

Hello,

We are working on a project where company wants to use Dynamics CRM as a master customer database.

Company consists of 3 different business units and they have same customers and different customers (Accounts).

Every business unit have their own Account Managers and for some of their customers (Accounts) there is an Account Manager from every Business Unit.

Any ideas how we should manage the ownership of the records (as we know crm records can only have one owner)?

Options we have considered:

- Ownership of the records are assigned to an ownership team that consists of crm administrators from the business units (3 pcs)

- 3 different lookup fields from Account form to crm users

- Then we should fix the views according to these (My Accounts, ..)

Any tips or ideas what we should consider or how we should build the CRM environment according to this particular case are more than welcome.

Thank you in advance.