Many foreign companies and foreign purchased UK companies are here because we are in the EU and because English is now the Lingua Franca and most top managers have it as their second language.
However, once the main reason they moved to the UK - its membership of the EU - goes that will not stop them making the sensible business solution of building new plants in EU countries and gradually withdrawing from the UK market. Some, like Jaguar Landrover, have already made that decision.
I am not a supporter of another referendum but as the evidence builds up for the utterly incompetent and deliberately misleading and frequently dishonest way both sides put their cases and the extent that the electorate was lied to, again by both sides. The justification for a complete rerun of the referendum, with international observers in the country able to comment on the arguments of both sides and all those individuals and companies involved the first time round banned from any involvement in the campaign, is becoming compelling.