Austria's central bank chief Ewald Nowotny (pictured above) said Thursday a possible British exit from the European Union could have dire consequences for London as a financial hub.

"You have to see that a Brexit would - at least in my view - be coupled with the financial hub in London losing its current privileges," he said in Brussels.

"And we know that the City is of no small importance for the British economy," the ECB governor added, alluding to the fact that London contributes the lion's share to the nation's tax income.

Luring skilled labor

Concerns about a looming Brexit were also voiced by officials at a leading technology company ARM Holdings, the most valuable tech firm listed in London.

They said a Brexit would hinder their ability to employ the scientists and engineers it needs. ARM, which designs the chips that power nearly all of the world's smartphones, said around 300 of its employees in Cambridge came from mainland Europe, some 10 percent of its highly skilled workforce.

"Our main concern is the ability to attract talent and be able to get the necessary papers for them to work in the UK in the event of Brexit," Chief Financial Officer Chris Kennedy said in a statement.

So far, it's unclear whether visas would be introduced for workers from EU member states. Britain's Prime Minister David Cameron promised voters to decide whether the country should remain in the bloc in a referendum that could be held as early as June.

hg/cjc (Reuters, dpa)