Northwest Airlines Corp. has been subpoenaed by the Department of Justice in a probe of possible air cargo price-fixing, the carrier said.

More than a dozen airlines have been the subject of an investigation initiated by US and European Union officials into suspected price-fixing in the air cargo industry on surcharges for fuel, security and insurance. Northwest, which runs the largest cargo business of any of the US passenger airlines, had not been publicly identifi ed as a target in the probe.

Northwest spokesman Dean Breest said that the airline received a subpoena from the Department of Justice in the spring of 2006 and that it is cooperating.

A Justice Department spokeswoman confi rmed that the air cargo probe is ongoing but declined to comment further. In September, United Airlines and American Airlines disclosed settlements that did not involve payments in a lawsuit that arose from the investigation. Lufthansa AG paid US$85 million to settle pending lawsuits in the case.