Matson Navigation, the biggest ocean cargo carrier to Hawai'i, said it expects to receive a subpoena from the U.S. Department of Justice as the government investigates pricing practices of ocean carriers serving Puerto Rico.

"Matson Navigation, A&B's ocean transportation subsidiary, does not operate vessels in the Puerto Rico trade," said Matson's parent company, Alexander & Baldwin Inc., in a press statement.

"However, Matson has been informed by the Department of Justice that it will receive a subpoena for documents related to domestic ocean carriage. We will cooperate fully with the Department of Justice."

On Thursday federal agents searched the offices of Horizon Lines Inc. in connection with the probe. Authorities took computers and boxes from Horizon's headquarters and were armed with search warrants and a grand jury subpoena.