Hawaii’s biggest ocean cargo transportation firm, Matson Inc., is facing a June 30 deadline to reach a new contract with three unions representing crewmembers on its ships.

The company said it believes sufficient time remains to work out agreements that would avoid any disruption in service, and characterized a recent vote by the unions to authorize a strike as part of the negotiating process.

Matson is negotiating labor agreements with the Sailors’ Union of the Pacific, the Seafarers International Union and the Marine Firemen’s Union.

The current 5-year contract with the unions and Matson was reached in 2008 on the day the prior contract was set to expire.