AMSTERDAM, Netherlands — A Dutch shipping company negotiated with Somali pirates today, seeking the release of nine crew members on a freighter that was hijacked in the latest attack on merchant shipping off the coast of Somalia.

Lars Walder, spokesman for the ship's owner Reider Shipping BV, said his company is in contact with the hijackers and "as far as we know none of the crew has been injured or worse."

The crew were four Russians and five Filipinos, he said.

The ship, the MV Amiya Scan, is chartered by a Danish company, Scan-Trans Shipping, and sails under a Panamanian flag of convenience. It departed Kenya on May 19 on its way to Romania and was hijacked Sunday in the Gulf of Aden.

The Amiya Scan was the sixth ship hijacked by Somali pirates in two months. Since Jan. 1, 24 ships have been hijacked in the Gulf of Aden, compared with 44 for all of last year.

Globally, 157 hostages have been taken by pirates and released unharmed this year before the Amiya Scan hijacking, said Pottengal Mukundan, director of crimes services.

Neither the company nor the agency would discuss details of the seizure of the Amiya Scan or the negotiations.