Two Kyoto firms have been ordered to suspend business for three months because they failed to identify themselves or the nature of their e-mail when transmitting unsolicited commercial missives, a government official said Wednesday.

It is the first time the Ministry of Economy, Trade and Industry has ordered firms to halt operations for sending spam. The METI official said the firms sent a total of 400,000 e-mail messages a day to an unspecified number of people introducing dating and paid Web sites featuring sexually explicit images. Net-based pay services are considered mail-order services and e-mail introducing them is deemed to be advertising.

Firms are required by law to include their name and post "unsolicited advertisement" in the message subject line, but the two Kyoto firms rarely complied with these conditions.

METI tracked down the spammers and found that the two firms -- SKI and Asian Oasis -- had the same operator, Yuichiro Sakamoto.

He admitted violating the law, the official said.

Apart from the suspension order, the ministry urged SKI to improve operations after it found that e-mail recipients could be transferred from the message to its Web site where a contract could be signed. However, no confirmation message appeared when the contract was signed.

Payments, including the 50,000 yen admission fee, to this site by a single customer could reach 920,000 yen over a three-month period.

Of the estimated 1 billion e-mail messages handled by one major domestic Internet provider, some 800 million are spam, according to METI.