According to The Wall Street Journal, the union was attempting to negotiate a three-year agreement of wage increases, improved safety conditions and burdensome staffing issues. Additional talks between companies and local unions would be based on the deal.
The United Steelworkers union rejected several propositions from the oil giant Shell that led negotiations on behalf of refinery operators, The Wall Street Journal said.
However, the union officials said the employers' stance does not reflect the workers' interests.
"Industry's new proposal is insulting and fails to address issues that matter to members. All units instructed to reject. Clock is ticking," the union told its members late Saturday in a text message, as quoted by the media outlet.
The strike came amid low global oil prices. Since last June, the prices dropped significantly due to market oversupply. During a November 2014 meeting the Organization of the Petroleum Exporting Countries stated it would not change oil output levels, causing a further slump in crude prices.
Oil prices currently stand at $48.24 per barrel of WTI and $52.99 per barrel of Brent, according to Bloomberg.
