Investors cheered news of the deal and pushed Facebook shares up 1.8%, while several powerful Democratic lawmakers in Washington condemned the proposed penalty as inadequate.
China, the world's biggest steel producer, has ordered mills in key regions, including Beijing-Tianjin-Hebei, the Fenwei Plain and the Yangtze River Delta.
O'Leary predicted a return to service by July but the U.S. Federal Aviation Administration has since reported a new potential safety risk that it says must be addressed first.
The premium for 380-centistoke (cst) high-sulfur fuel oil rose to $11.63 a ton above Singapore benchmark prices on Thursday, according to Reuters data.
Trade across global markets was expected to remain subdued following the Independence Day holiday in the United States on Thursday and ahead of the non-farm payrolls report.