Business partners

If you go shopping at Amazon.com, you will find some other vendors or sellers.

e.g. http://www.amazon.com/gp/offer-listing/B00009X6PH/ref=dp_olp_new?ie=UTF8&qid=1236478936&sr=8-1&condition=new

Is there a special term for these vendors?

Can you call them joint ventures, affiliates or business partners?

Any better suggestions?

Thanks