NEW YORK (AP) – Delta Air Lines will pay a $38-million fine to settle criminal accusations that the cargo unit of Northwest Airlines conspired to fixed prices, the Justice Department said on Friday.

Northwest met with other airlines at least from 2004 to 2006 to fix cargo prices between the US and Japan, according to the charge filed on Friday in US District Court in Washington. Meetings were also held to make sure the haulers were complying with the agreed-upon rates, according to the charge.

At the time, Northwest ran a stand-alone cargo unit with Boeing 747s that flew to Asia. It was the only US carrier with a dedicated freighter fleet, but it was shut down last year. Airlines often carry cargo in their bellies along with luggage.

Northwest Airlines LLC, a unit of Delta Air Lines Inc., pleaded guilty to the charge, the Justice Department said. Delta bought Northwest in 2008, and the two carriers have been combined.

In a statement, Delta said Northwest had "terminated the employment of the individual who it believed had primary responsibility for the conduct in question.''

Delta said the Justice Department did not allege misconduct by any current or former officer or director at Northwest or Delta.

The Justice Department said the airline had agreed to cooperate with its ongoing anti-trust investigation.

The Justice Department says more than a dozen airlines have pleaded guilty and paid more than $1.6 billion in criminal fines.

On Wednesday, a lawyer for freight shippers said American Airlines had agreed to pay $5 million to settle a class-action lawsuit over price-fixing.