Banking group UBS claimed that the botched stock market listing of Facebook cost it 349 million Swiss francs (£227m).

Zurich-based UBS, which has 6000 UK staff, blamed the loss on the mishandling of the flotation by Nasdaq, which involved a series of technical errors that caused a delay in the start of trading in May.

UBS reported a 40% slide in pre-tax operating profits to 2.3 billion Swiss francs (£1.5bn) in the six months to June 30, after the Facebook investment pushed its investment bank to a 130m Swiss franc loss in the second quarter.

The bank said it would take legal action against Nasdaq over the Facebook flotation and it intended to pursue compensation for the full extent of its losses.