Switzerland has proposed an "F4" alliance of leading financial centres outside the European Union - made up of Singapore, London, Zurich and Hong Kong.

The Swiss Bankers' Association (SBA), which has floated the idea, said yesterday that such an alliance would discuss issues regarding EU market access and the setting of international standards, and would foster dialogue on the financial sector's role.

Switzerland is reaching out to London as the British referendum vote to leave the EU throws into question whether British-based banks will be able to offer financial services across the EU.

Switzerland is facing its own issues of EU market access. It rejected EU membership in 1992, relying instead on a web of bilateral agreements with the bloc.

These deals have come under threat after the electorate voted for quotas on immigration from EU countries, which violates the EU's cherished principle of free movement of people.

The Swiss-EU talks have been under way for two years, but the EU looks determined to deny Switzerland access if it imposes immigration controls.

The F4 concept, reported by the Financial Times last week, had been proposed by SBA chairman Patrick Odier from as early as 2012, the association said.

An SBA spokesman told The Straits Times that the idea emerged from the Swiss Banking Global Conference in 2012.

Mr Odier had proposed the alliance as "it would make sense for financial centres to team up for their voices to be better heard in international discussions", she said.

The spokesman added that while there was ongoing dialogue with the financial centres, she could not confirm if the initiative was being discussed.

Proposals for an alliance have not yet been tabled, she said.

The Straits Times understands from key industry players in Singapore that they have not been approached by the SBA.

A Hong Kong Exchange spokesman also told The Straits Times that "HKEX does not have details of the proposal and is therefore not in a position to comment on it".