European equities retreat as U.S.-Iran ceasefire shows strain

European stocks fell after a brief rebound as signs of strain in the U.S.-Iran ceasefire surfaced: the Stoxx 600 slid about 0.4% at the open, with the FTSE 100 down 0.1%, CAC 40 down 0.5% and DAX down 0.9%; travel names Lufthansa and TUI shed around 3.5% each, while Asia traded lower amid the tensions.