The USW said lead oil company negotiator Royal Dutch Shell Plc failed to bring experts and information as promised when talks ended last week.

In a statement posted on the union website, the USW said its negotiators engaged in a "discussion about the industry's failure to bargain in good faith and their game playing regarding our legitimate requests for information."

The union then made a proposal to eliminate non-union contracts and increase staffing at refineries and chemical plants to assure safe operations, according to the USW.

Shell representatives told the union more time would be needed to study the proposal and they would not agree to language that restricts owners' ability to staff their plants as they see fit, according to the USW statement.

A Shell spokesman did not have an immediate comment about the USW's statement.

The two sides have been unable to agree since talks started on Jan. 21 on the size of wage increases and how to monitor worker fatigue, which is tied to accidents and can be handled through overtime pay or adding workers.

Shell's U.S. arm is the lead representative for oil companies at the negotiations for a three-year pact that would cover 30,000 workers at 63 refineries that together account for two-thirds of U.S. refining capacity.

Over the weekend, walkouts widened to include BP Plc's Whiting, Indiana, refinery and its joint-venture refinery with Husky Energy in Toledo, Ohio.

In total, strikes have been called at 11 plants, including nine refineries that account for 13 percent of U.S. refining capacity. About 5,400 workers are now on the picket lines in the first big refinery strike since 1980.

Companies have called on trained managers to keep their plants running at nearly normal levels, except for Tesoro Corp, which opted to shut its Martinez, California, refinery as part of an already ongoing overhaul.

(Reporting By Erwin Seba and Terry Wade; Editing by Cynthia Osterman and Lisa Shumaker)

Stocks treated in this article : Tesoro Corporation, Husky Energy Inc., BP plc