LONDON, July 10 (Reuters) - A coordinated move by stock markets in the European Union and Britain to catch up with Wall Street by halving the settlement time for transactions could realistically happen in late 2027, an EU regulatory hearing was told on Wednesday.

Trades on the London Stock Exchange, Deutsche Boerse, Euronext and other bourses in Europe take two business days to settle, lagging one business day (T+1) in the United States since May.

The European Securities and Markets Authority, the bloc's markets watchdog, held a hearing on Wednesday where a poll of participants overwhelmingly backed an option to complete T+1 in the fourth quarter of 2027.

Britain has targeted the end of 2027 at the latest, and later this year the EU's executive European Commission is expected to propose a date, with technical preparations already underway.

"Q4 2027, with all that is already happening, I think is realistic, I don't think it's too much of a stretch," Sebastijan Hrovatin, a senior official at the European Commission, told the hearing, adding that a final decision would be up to the EU states and the European Parliament.

Andrew Douglas, head of Britain's T+1 industry group now compiling recommendations for UK regulators, said these would include a move date "that is looking increasingly like the back end of 2027, probably September, October."

Douglas said he was not sure how the EU and UK could formally cooperate given post-Brexit political sensitivities, but it was necessary for both to align with the United States.

Douglas said for EU-UK coordination to take place, the EU needed to "pick a date and stick with it", as advised by U.S. Securities and Exchange Commission Chair Gary Gensler.

The perceived success of the U.S. move has led to a "voluble lobby" in Britain calling for a shift in 2026, but Douglas said that "realistically, I am not sure that's on the table".

Initially, Europe's funds industry body EFAMA was lukewarm to T+1, but it told the hearing that its views have evolved after Wall Street's successful shift, with over half the world's equity trading now on T+1.

Vincent Ingham, EFAMA's director of regulatory policy, said a need to preserve competitiveness in European markets made a compelling case for the EU "to move as quickly as practically and operationally feasible to T+1, co-ordinated with the UK and Switzerland."

(Reporting by Huw Jones Editing by Christina Fincher)