NORFOLK, Virginia (Bloomberg) - EBay Inc., the world's largest online auctioneer, must pay about $30 million for violating a Virginia company's patent on an online shopping method through use of its "Buy It Now" feature, a federal judge ruled.

US District Judge Jerome Friedman in Norfolk, Virginia, yesterday rejected EBay's request to overturn a jury's 2003 finding that the company had deliberately infringed MercExchange LLC's patented way of making online purchases at a fixed price rather than through auction bids. Friedman had previously ruled that EBay can continue to use the Buy It Now feature.

MercExchange President Thomas Woolston called the ruling "another important milestone in our battle to defend our rights as a patent holder."

MercExchange said in a statement today that it also has requested damages for infringement since the 2003 verdict. MercExchange said it estimates Buy It Now sales account for 39 percent of EBay's revenue.

The dispute, begun in 2001, led to a landmark US Supreme Court ruling that said patent owners, while entitled to damages, cannot always keep an infringer from using their inventions. The high court said it's up to the judge in each case to decide when.

After EBay lost at trial, Mr. Friedman refused to order the company to stop using the patented technique. An appeals court said he must issue the order, following a decades-old principle that court orders to stop patent infringement are virtually automatic. The Supreme Court in May 2006 overturned the appeals court, and the case was sent back to Friedman.

In July, Mr. Friedman decided that EBay could continue to use the Buy It Now feature notwithstanding the jury determination that it violated MercExchange's patent. MercExchange, based in Great Falls, Virginia, was not harmed by the decision because it made money licensing patents, Mr. Friedman said.

In a statement, San Jose, California-based EBay said it will appeal Friedman's decision.

"We intend to appeal the court's ruling on the procedural issues and remain confident that after the appeal, the court will consider our arguments on their merits," EBay said in a statement on Tuesday.