The site, sothebys.com, will offer an online platform for auctioning art, antiques, and jewelry and is aimed at complementing Sotheby's core live auction business.

David Redden, executive vice president of Sotheby's in New York, said the site's 1,500 charter members represented a significant portion of the world's art dealing elite.

"That's an overwhelming number when you think that a great antiques show might have 70 dealers involved in it," he told Reuters in an interview.

Sotheby's announced in January that it was launching an Internet auction business, joining the flurry of companies rushing to capitalize on electronic commerce.

Its first online auction will be baseball memorabilia from collector Barry Halper's collection, which will take place via the Internet and also a live auction in New York.

The company plans to make an initial investment of more than $25 million for personnel, marketing and capital costs for the Internet venture over the next 12 months.

Sotheby's said this outlay will weigh on earnings, but it declined to put a figure on the impact.

Only professionals will be allowed to sell on the site, although anyone will be able to buy over the Internet. The site will initially focus on goods with auction prices of $300-$10,000, with bidders paying by credit card.

Asked whether clients would be willing to buy works without having actually seen them in person, Redden pointed out that many bidders already buy their works via catalog.

"The imaging has become so good on the Internet that it rivals that of the catalog," Redden said, adding that the Internet also allows for increased text and pictures.

Sothebys.com will be headed by Susan Solomon, former chief executive of Sony Worldwide Networks.

The launch of sothebys.com follows the U.S. stock market flotations of auction services uBid Inc and eBay Inc. However, Sotheby's expects little overlap between its high-art business and that of existing online auctioneers.

For example, uBid offers mostly close-out and refurbished consumer electronics, while eBay matches buyers and sellers for a range of items from Hollywood memorabilia to antiques.

"As far as auction sites that deal with higher quality works of art, this is really a very empty area," Redden said.

Eventually, as online technology develops, the Internet site might complement or even replace phone-in bids at live auctions.

"We have a great number of people who bid over the telephone, but they obviously can't see what's going on. The Internet can actually provide a very enhanced access to the auction process eventually," Redden said.