As the storm closes in on New York City several banks have made preparations to shift their trading activities to London, according to Dow Jones.

Closures of the transport systems in New York have meant that many traders have been unable to get into the office on Monday, which poses a challenge for banks in the currency market, because clients have standing orders that are triggered when prices pass through designated levels.

However, Citigroup, the world's second-largest foreign exchange bank, has said that its London trading operations will be 'picking up the slack'.

Australia's Westpac Institutional Bank won't have any of its 40 New York staff at their desks when Sandy hits. It said: "We will be covering the US time zone out of London and out of Sydney, so we'll just run longer out of London."

"It's very seamless to be able to cover for each other and pass books off electronically."