The boss of Nissan has said future decisions about the car giant's Sunderland plant will depend on the outcome of Brexit negotiations.
But Carlos Ghosn said he was "reasonably optimistic" that the UK will continue to be a key partner of the European Union.
He said "most companies" will be waiting to see what happens before making decisions about investments.
Mr Ghosn told the BBC: "Well I don't think today you can talk about any impact before we see what is the new status of the UK. The question of Sunderland - Sunderland is a plant which is a European plant based in the UK.
"Most of the production out of Sunderland is exported to Europe. So obviously for us the relationship which is going to prevail between the UK and Europe is very important. So the future investment decisions are going to depend a lot into ... Okay, the UK is out of Europe. Fine. But what's going to be the new status?
"So you're going to see a period where most companies are going to be waiting to see what's going to be the new status."
A stunning win for Leave in Sunderland came despite warnings from Nissan about the consequences of Brexit.
More than six out of 10 people who voted in the North East's largest city opted to turn their back on the EU.
At the time, Nissan declined to comment on the British people's choice and the implications, but previously made it plain Remain was its preferred option for jobs and trade.
The Japanese manufacturer employs 6,700 people at its Wearside plant, the most productive in Europe, with another 30,000 in the supply chain employed elsewhere in the region.