(Reuters) - The United Steelworkers union (USW) on Friday called strikes at BP Plc's (>> BP plc) plants in Whiting, Indiana, and Toledo, Ohio, taking to 11 the number of refineries and chemical plants affected by the first nationwide industrial action in the oil industry since 1980.

The additional walkouts will begin on Saturday, and BP has said it has trained replacement workers to ensure operations to continue.

The dispute centers on a new national contract that covers workers at 63 refineries, accounting for two-thirds of U.S. refining capacity. The nine oil refineries account for 13 percent of U.S. capacity.

The list also includes the refineries with the worst fatal accidents in the past 10 years. Marathon Petroleum's Galveston Bay, Texas, Refinery was previously owned by BP. Fifteen workers were killed in 2005 blast at what was then called the BP Texas City Refinery. A 2010 explosion at Tesoro's Anacortes, Washington, refinery claimed the lives of seven workers.

The companies have said replacement workers would be called in to keep operations running normally at all plants except for Tesoro's Martinez, California, refinery, which will be shut as part of it was already undergoing a turnaround.

The walkouts mark the first in support of a national accord since 1980.

Below is the list of the 11 plants:

================================================================================

Refineries

================================================================================

Company Location Capacity (BPD) Status

================================================================================

Lyondell Basell Houston 263,776 Operating

Marathon Petroleum Catlettsburg, Kentucky 242,000 Operating

" " Galveston Bay, Texas 451,000 Operating

Shell-Pemex Deer Park, Texas 327,000 Operating

Tesoro Anacortes, Washington 120,000 Operating

" Carson, California 251,000 Operating

" Martinez, California 166,000 Shutting Down

BP Toledo, Ohio 160,000 Operating

BP Whiting, Indiana 413,500 Operating

=============================================================

Total Capacity (BPD): 2,394,276

=============================================================

Plants

=============================================================

Company Name Location

=============================================================

Marathon Petroleum Green Co-Gen Plant Texas City, Texas

Shell Chemical Plant Deer Park, Texas

(Reporting by Erwin Seba in Houston, Jessica Resnick-Ault and Josephine Mason in New York; Compiled by Terry Wade; Editing by Andre Grenon and Grant McCool)