** Shares of U.S. energy companies fall premarket, as oil slides after U.S.-Iran ceasefire
** Oil falls below $100 after Trump agreed to a two-week ceasefire with Iran that was subject to the immediate and safe reopening of Strait of Hormuz
** Shares of Exxon Mobil XOM.N and Chevron CVX.N down 6.3% and 4.6%, respectively
** Oil and gas producers Occidental Petroleum OXY.N, Devon Energy DVN.N, Diamondback Energy FANG.O and ConocoPhillips COP.N fall between 5.6% and 7.8%
** Oilfield services companies Baker Hughes BKR.O and SLB SLB.N down 2.6% and 4.1%, respectively
** Refiners Marathon Petroleum MPC.N and Phillips 66 PSX.N shed 5.5% and 5%, respectively
** Brokerage Roth MKM downgraded its rating on some oil stocks, saying oil likely peaked, adding "stocks have run hard"
** Rating changes were made on the following cos: