"As a public official, I take no position on Brexit per se," he said. "But I do have to point out consequences."
He went on: "The impact on trade seems to be more in goods than services... But it underlines why we must be alert to and welcome opportunities to rebuild relations while respecting that very important decision of the British people."
The government remains opposed to rejoining the EU, but Chancellor Rachel Reeves also said in her Mansion House speech there could be a closer relationship.
"Our biggest trading partner is the European Union. We will not be reversing Brexit, or re-entering the single market or customs union. But we must reset our relationship," she said.
Mr Bailey said that the UK should not focus "just on the effects of Brexit", warning about "geopolitical shocks and the broader fragmentation of the global economy".
He made a similar comment last week when asked about US President-elect Donald Trump and his threat to impose tariffs of up to 20% on imports.
Vicky Pryce, chief economic adviser to the Centre for Economics and Business Research, said if that were to happen, "it is actually quite questionable whether the UK could have a special relationship with the US when it still trades quite substantially with Europe".