Multiple administrator for one installation

I'm trying to create an ecommerce site where multiple companies can list products and fulfill orders. In a sense there's a common db and common template but when individual company log in to their admin account they they would only see orders for their own products and carry out admin functions only for their customers, products, etc.

I willing and able to get my hands dirty in the code. Any pointers would be greatly appreciated.

Just providing additional clarifications: what is needed is more like Amazon's zShop or eBay Store functionality, where there is a common ecommerce market where companies can participate.

chuender:

Just providing additional clarifications: what is needed is more like Amazon's zShop or eBay Store functionality, where there is a common ecommerce market where companies can participate.

Looking to form an ebay or amazon or an ecreater company?
A friend of mine asked me the same hopefully the big ones at zen can tell us if this is possible with zen

I'd like to work with Zen-cart since I already have some good experience with it. But I'm also open to trying other open source platforms.

Am very interested in this too ! Anyone find anything out yet ?

Got to thinking more about this and here are some more specific high level functions:
Creation of a Zen-Cart, osCommerce or CRE Loaded based ecommerce site with the following features:
Administration

• Site supports multiple admin accounts for multiple individual companies. Individual admin account manages account-specific products, customers, orders, etc.
• Site lists products uploaded and managed by multiple companies.
• There is a master admin account for managing the site – templates, categories, payment modules, shipping modules, etc.
• Site should remain compatible to standard 3rd party modules, especially the common ones like Easy Populate.
  Catalog
  • Individual companies have their own “Store” page. Look and feel of the Store page is managed by templates.
    Order-To-Pay for orders with products offered by more than one company
  • When a customer places an order with products offered by more than one company, the customer can select company-specific shipping method offered by the companies. In a sense, in this case the customer is essentially placing multiple orders on one checkout transaction. The order will be billed to the customer as one transaction.
• When an individual company log in to their admin account they should only see their portion of the order, i.e. line items for the company’s products. Ecommerce transaction fees and shipping costs also needs be partitioned.
  In a sense, we are looking to create something similar to Amazon Webstore or eBay Store.
  

I'm in the process of getting quotes from two programming firms. Would anyone be interested in sharing the cost?