Shorter hours would not be in the best interests of investors or stock markets, European bourses said today, dashing hopes at banks and investment companies in London of cutting 90 minutes from the trading day.
The Federation of European Securities Exchanges (FESE) said shorter hours would be a move in the wrong direction.
The current European trading day is 9am to 5.30pm continental European time, longer than in Asia or Wall Street.
This means that share trading spans the Asian market close and the open on Wall Street, and a shorter day could put Europe at a competitive disadvantage to rival trading venues in other parts of the world, FESE said.
The London Stock Exchange, which is not a member of FESE, held a public consultation earlier this year that found broad backing for cutting the trading day by 90 minutes to improve mental wellbeing and help attract more women on to trading floors.
But without a harmonised approach across Europe, the goals of shorter hours would be harder to achieve given banks have pan-European trading desks, the LSE has said.
The LSE declined to comment on FESE's statement.
London will also be wary of putting itself at any competitive disadvantage to rival exchanges in continental Europe now that Britain has left the European Union.
FESE said the length of the trading day did not have a negative impact on the working culture of trading and that a better work-life balance could be achieved if companies adopted other measures such as adding more shifts.
US exchange Nasdaq, which operates the Stockholm bourse, said shortening hours would be "misguided".
It said that any change would need to be a pan-European decision that also included off-exchange trading platforms.
Britain's Investment Association and the Association for Financial Markets in Europe, a banking lobby, reiterated their calls this week for a cut in trading hours.
Pan-European Exchange Euronext has just completed its own public consultation on market hours.
Euronext, which is a vice-president of FESE, has already expressed scepticism about what it has called a "London proposal."