The two companies first announced the joint venture at the end of January. At that time, the companies said the site was an attempt to put more expensive art offerings on eBay while driving more customers to Sotheby's Web site.
Kevin Pursglove, spokesman for eBay, said Sotheby's will integrate eBay's live auctions technology on a site that will be built and hosted by eBay.
The new site, Sothebys.com, will exist within eBay rather than operate as a separate entity, he said. However, the site will be marketed by both companies.
Customers will be able to register at eBay to participate in Sotheby's online auctions.