PORTLAND, Ore. (AP) -- Shipping companies are deciding whether to bypass the Port of Portland because of a strike threatened Sunday by marine terminal security guards represented by the International Longshore and Warehouse Union.

The port plans to replace the 25 workers during the strike, but picket lines are expected to shut down the three terminals where they work.

Talks with a state government mediator are planned Saturday in hope of heading off the strike.

Port of Portland spokesman Kama Simonds says vessel schedules are fluid, and it's anticipated that some might arrive early to avoid the strike.

Hapag-Lloyd's Cape Manila container ship arrived in Tacoma on Wednesday. According to an online schedule, it's due in Portland early Friday and expected to leave Saturday.

The Hanjin Geneva remains on schedule to arrive Sunday evening.

Copyright 2012 The AP.