Both companies said that they moved swiftly to have the ads removed after they were discovered by the Los Angeles-based Simon Wiesenthal Center, a group which monitors anti-Jewish and other hate groups and has increasingly focused its attention on the Internet.

An Iran-linked militant group, Hizbollah waged a war of attrition against Israel during much of its 22-year occupation of a buffer zone in south Lebanon. Israel pulled its troops out in May. The State Department lists Hizbollah as a "terrorist" group. Earlier this week, the Wiesenthal Center told the two companies that their ads were on a Website for a Lebanese television station ManarTV (http://www.manartv.com), which is backed by Hizbollah and freely states it is at war against what it calls "the Zionist enemy."

"Obviously Amazon and Microsoft had no idea who these people are," said Mr Abraham Cooper of the Wiesenthal Center. "The bottom line is that they are both severing the relationship." Both Amazon and Microsoft said ManarTV appears to have obtained use of their ads by participating in affiliate programs, a popular way of driving online business in which other Websites agree to post banner ads in exchange for a percentage of the revenue those ads drive.

"They applied for participation in our associates program and just said they were a Lebanese television station," said Amazon spokeswoman Ms Patty Smith.

She said Amazon lists guidelines for associates, and requires that they are not affiliated with any groups promoting violence or illegal activity.

Reuters