OAKLAND -- Dozens of longshoremen at the Port of Oakland picketed for a few hours Tuesday, blocking ships at some berths from being unloaded and trucks from delivering shipments.

Pickets are opposing a legal settlement before the Board of Port Commissioners on Thursday that they say will cost union jobs.

A port spokesman said an arbitrator had ruled there was no reason for International Longshore and Warehouse Union (ILWU) Local 10 and Local 91 to be picketing Tuesday and ordered workers back to work.

Mike Villeggiante, ILWU Local 10 president, said the protest was two hours Tuesday and will not be repeated Wednesday. But workers refused to adhere to the ruling and took their grievance to coastwide arbitration, he said.

The settlement would give control over two terminals to an operator that provides fewer jobs to ILWU members.

The protest began just before 7:30 a.m. Tuesday when longshoremen picketed outside APL terminal Middle Harbor Road where trucks deliver and pick up supplies.

The pickets remained peaceful, although a long line of trucks could be seen backed up in the port area through the afternoon.

Contact Rick Hurd at 925-945-4789 and follow him at Twitter.com/3rdERH. Contact Natalie Neysa Alund at 510-293-2469 and follow her at Twitter.com/nataliealund.