The animal welfare group said it first brought its concerns to Amazon.com's attention almost a year ago, urging the online retailer to remove The Gamecock and The Feathered Warrior from its Web site.

The Washington D.C.-based organization argues that Internet sales of the magazines violate the federal Animal Welfare Act, which bars use of mail or other means of interstate commerce to promote animal fighting, unless it's performed outside the United States.

"That's their claim, and we don't agree with their claim, so we're going to continue to make these titles available," Amazon.com spokeswoman Patty Smith said Tuesday afternoon. "It's up to the customer to determine what they feel is appropriate for them to purchase."

Smith said the company realizes that some people will find certain goods Amazon.com sells objectionable, but that it remains committed to fostering free speech and offering its customers as wide a selection of merchandise as possible.

"No one respects free speech more than we do, but inciting criminal cockfighting is not protected speech, and cannot be tolerated," Jonathan Lovvorn, the Humane Society's vice president of animal protection litigation, said in a statement released Tuesday.

Lovvorn said the group was ready to file its lawsuit seeking a court order forcing Amazon.com to pull the magazines, but was holding off a week or two to give the company a chance to respond.

In June, Amazon.com and other Web merchants agreed to pull a DVD featuring violent pit bull fights, after the Humane Society asked authorities to investigate whether the video violated a federal law against interstate or foreign commerce profiting from the depiction of animal cruelty.

A search for "Hood Fights, Vol. 2, The Art of the Pit" on Tuesday confirmed the DVD was no longer for sale on Amazon.com.

As of early afternoon, The Gamecock ranked 147th out of more than 17,000 magazine titles on Amazon.com, while The Feathered Warrior ranked 2,090th.