Congress should pass a law effectively overturning a 2007 decision by the U.S. Supreme Court saying that so-called vertical price-fixing isn't necessarily a violation of U.S. antitrust law, representatives of eBay, Burlington Coat Factory and the U.S. Federal Trade Commission said.

That Supreme Court decision, in , hurts small and medium-size Internet sellers trying to compete with established retailers, said Tod Cohen, eBay's vice president and deputy general counsel for government relations. The court's decision went against 96 years of antitrust law, he said.

Retail pricing agreements "guarantee that consumers will pay higher prices" on a wide variety of products, added Pamela Jones Harbour, a member of the FTC. "Consumers usually do not realize they pay substantial retail-price management [RPM] premiums."

Old-line manufacturers and retailers are threatened by the Internet, where innovative small companies are using technology to drive down prices, Cohen said. But with the Leegin decision, many manufacturers are hunting down online retailers selling below set prices and cutting off their supplies, Cohen said.

"There is evidence that small and midsized Internet retailers are the primary target of aggressive RPM policies," Cohen said. "Many eBay sellers have been targeted by manufacturers and large retail partners with various tactics to take down their listings and discredit their sales."