European stocks closed in negative territory Thursday, as airline shares were punished after a profit warning from EasyJet PLC, but bank shares rebounded.

U.S. stocks flatlined on Thursday as investors abstained from making big bets ahead of Friday's much-anticipated September jobs report. Stocks sold off in early trade, but the market recouped much of its losses after a high-ranking European Central Bank official repudiated reports that the central bank had discussed tapering its bond-buying program.

Market worries sent Asian equities broadly lower early Friday, as increasingly heated discussions over the U.K.'s exit from the European Union saw the pound plunging against the U.S. dollar. The selloff began after French President François Hollande called for tough negotiations with the U.K. as it leaves the EU. Britain wanted to leave the bloc "but doesn't want to pay," which was "not possible," Mr. Hollande said in comments cited by Sky News.