Moody's Investors Service revised its 12 to 18-month outlook for the U.S. steel sector to positive from stable, citing a range of factors, including reduced imports following the news from the White House Thursday that it is imposing a 25% tariff on steel imports from Canada, Mexico and EU. Improved demand levels from 2017 have continued in 2018, said Moody's senior vice president Carol Cowan, the lead author of a new report. Capacity utilization stood at 75.7% in the week to may 19, above the 73.7% level at the same time last year, she said. "We expect capacity utilization to range between 73% and 77% in 2018," said the report. "While that is below the sustained 80% or higher mark we use as one of the triggers for a positive outlook, we expect continued improvement as markets remain strong and import levels start to recede following final rulings on Section 232 import tariffs and exemptions." Steel prices are holding at levels that will allow producers to be solidly profitable and to generate cash flow, said Cowan. United States Steel Corp. shares were up 3.5%, while AK Steel Holding Corp. was up 1.5%. The S&P 500 was down 0.4%.