Concerns over looming congestion has prompted G6 container shipping alliance members APL, Hapag-Lloyd, Hyundai, MOL, NYK and OOCL to drop Oakland on the next four sailings of its Pacific Atlantic 2 (PA2) service between Asia, Central America, and the United States east and west coasts.

Port spokesman Mike Zampa said ships have had to go to anchorage instead of to berth. Ships at anchor ranged from four to 10 in the last two weeks, he said.

The G6 affected sailings are: the MOL Endeavor (v.069e), ETA Oakland on July 8; MOL Efficiency (v. 072e), ETA Oakland on July 15; APL Turquoise (v.127e), ETA Oakland on July 22; and MOL Express (v.082e), ETA Oakland on July 29.

The G6 Alliance members said they will "continue to monitor the port of Oakland closely and reinstate the call when improvements are observed".

The PA2 service is operated with 10 vessels, including seven from MOL and three from APL with an average capacity of 4,559 TEU.

The full port rotation is Tokyo, Kobe, Busan, Balboa, Manzanillo (Panama), Miami, Jacksonville, Savannah, Charleston, New York/New Jersey, Norfolk, Manzanillo (Panama), Balboa, Los Angeles, Oakland and Tokyo.