Matson Inc. sailors and firefighters could walk off the job tonight if no deal is reached on a new contract.

A union spokesman said there is a 50-50 chance that the workers could strike beginning at 9 p.m. Hawaii time, or midnight on the West Coast.

The Sailors’ Union of the Pacific, which represents the navigators of the ships, and the Pacific Coast Marine Firemen, Oilers, Watertenders and Wipers Association, which represents members who work in the engine room, were scheduled to resume negotiations with the shipping company in San Francisco at 6 a.m. today Hawaii time, or 9 a.m. in California.

“We’re expecting to go down to the wire,” Anthony Poplawski, president of the Marine Firemen’s Union, said Thursday from San Francisco.

Keoni Wagner, spokesman for Matson, declined to comment on the potential for a strike.

Both unions operate under the same contract that’s set to expire at midnight in California, or 9 p.m. in Hawaii. Poplawski said his union represents approximately 150 Matson workers and the Sailors’ Union of the Pacific accounts for roughly 300.

“We told the company no contract, no work after midnight (9 p.m. Hawaii Standard Time),” said Gunnar Lundeberg, president of the Sailors‘ Union of the Pacific.

Lundeberg said the company and the union are still “poles apart” on wages, hours, working conditions and benefits. Lundeberg declined to comment on specific wage changes or hours being negotiated.

If the unions strike, ships out at sea would continue to their assigned ports, but dockworkers wouldn’t load or offload cargo in support of their fellow union workers, Lundeberg said. Picket lines also would go up at all shipping terminals in Hawaii and along the West Coast, and all cargo operations would stop, Lundeberg said. Other Matson unions are expected to support a strike.

A prolonged strike could deal a blow to Hawaii’s economy. Matson handles roughly two-thirds of all goods shipped to the state, where residents depend on ocean transportation for approximately 80 percent of all locally consumed goods.

Matson has served Hawaii since 1882. Currently, Honolulu Harbor welcomes eight Matson containerships from the West Coast every 14 days. Matson also serves Alaska, Guam, Micronesia and the South Pacific from distribution centers on the mainland.

In June the Sailors’ Union of the Pacific authorized the negotiation committee to call a strike, if necessary, at about the same time they began formal negotiations with Matson. The Marine Firemen’s Union is set to ask its members to authorize a strike this morning, Poplawski said.

The last strike called by the Sailors’ Union of the Pacific and the Marine Firemen’s Union occurred in the 1960s, Lundeberg said.