UBS, the European bank most affected by the US subprime crisis, surprised the market yesterday by saying it may be saved by a 3bn Swiss francs (€1.9bn) tax credit from posting a loss in the second quarter.

Some analysts estimated the Swiss bank, which has written off almost 38bn francs (€23.6bn) from its assets as a result of the credit turmoil, would post a loss of 4.56bn francs in the period on about 7bn francs in asset writedowns.

Chief executive Marcel Rohner, who has announced plans to cut 5,500 jobs and shrink the investment bank, is also trying to stem defections among wealthy clients after posting 25.4bn francs of net losses over the past three quarters. UBS said its money management division suffered client defections in the second quarter.

“UBS clearly wanted to show that it didn’t do that bad,” said Florian Esterer, a senior portfolio manager at Swisscanto Asset Management. “What worries me are the net new money outflows, which indicate a serious problem for the franchise.”

The Zurich-based bank sees no need for further capital because its Tier 1 capital ratio — a key gauge of a bank’s solidity that measures mainly shareholder’s equity against assets — stood at about 11.5pc at the end of June, up from 6.9pc in March. The ratio was buoyed after UBS raised 16bn francs in a rights issue within the past few months.

European banks may need to raise as much as a further €90bn to restore their capital after the US subprime mortgage collapse caused credit markets to seize up, Goldman Sachs said yesterday. Banks across the continent have already raised €73bn by going out cap in hand to investors after reporting €85.4bn in writedowns.

“Regulatory pressures and a sharp turn in the European credit cycle are the two main causes for concern,” the influential brokerage said.

Separately, the Bank of International Settlements (BIS), the central bankers’ bank, warned yesterday that defaults on loans that backed the recent boom in private equity buyouts may be “significantly higher” than ratings companies’ estimates