EBay Inc. will offer live online auctions of such items as jewelry, watches, prints, wines and photographs via a partnership with auction house Sotheby’s.

The online marketplace says that in “the near future” it will launch a feature on its site “tailored for collectors of rare, unique and premium art and collectibles, as well as first-time buyers.” Sotheby’s will anchor that part of the eBay site, and will operate a “new live auction feature and real-time biddings from anywhere in the world.”

Sotheby’s said that the number of its “lots,” which can be a single or a group of items, purchased by online bidders increased 36% year over year in 2013, and that online bidders competed for 17% of the lots sold by Sotheby’s in 2013. Additionally, mobile traffic accounts for 25% of the total traffic to the Sotheby’s web site.

“The growth of the art market, new generation technology and our shared strengths make this the right time for this exciting new online opportunity,” says Bruno Vinciguerra, Sotheby’s chief operating officer. “We are joining with eBay to make our sales more accessible to the broadest possible audience around the world.”

Sotheby’s and eBay say global online art sales could reach $13 billion annually by 2020. EBay operates its own “Collectibles” online store that sells not only fine art but baseball cards, antiques and coins.

The two companies are hardly the only participants in that scene. Last month, for instance, Invaluable LLC, a Boston-based firm that operates the Invaluable.com online auction site and also sells online auction software and services, raised $33.75 million in a Series D funding round. Invaluable focuses on the sale of fine art, antiques and similar collectibles on its auction site. Amazon.com Inc., too, operates, an online store where consumers can shop for fine art from some 4,500 artists and 150 galleries and dealers.