Washington ? Four companies agreed to repay customers a total of $300,000 to settle federal charges that they sold fake Internet addresses ending in “.usa” with an advertising campaign pegged to the Sept. 11 terrorist attacks.

The Federal Trade Commission said Tuesday that the companies – TLD Network Ltd., Quantum Management Ltd., TBS Industries Ltd., and Quantum Management U.S. Inc. – last year jointly sold Internet domain names ending with “.brit” and “.scot.” After Sept. 11, the companies began an e-mail campaign advertising “.usa” domain names, with statements such as, “Be Patriotic! Register .USA Domains.”

The FTC said the “.usa” domain names are not usable over the Internet and probably never will be. The settlement bars the firms, primarily based in London, from deceptive promotions and from selling their customer lists, the FTC said.

An attorney for the companies did not return calls seeking comment Tuesday.