SWITZERLAND IS searching for a new national bank chief after its chairman resigned yesterday amid ongoing controversy over insider trading allegations.

Philipp Hildebrand stood down yesterday as politicians prepared to question him about profits he and his wife made on dollar swaps last year.

Around the time of the deal, Mr Hildebrand was heading efforts to lower the value of the Swiss franc on foreign exchange markets. Mr Hildebrand produced documentation of the trades at his resignation press conference yesterday, but conceded he had no concrete proof that his wife had not known about the central bank’s plans to soften the franc.

“For that, all I have is my word of honour,” said Mr Hildebrand. “This step fills me with sadness . . . I go without rancour but, above all, more experienced than I was a few weeks ago.”

The purchase of $504,000 last August by Mrs Hildebrand, a former currency trader, earned the couple almost 75,000 Swiss francs (€62,000). Mr Hildebrand said he knew nothing of his wife’s trade and, on finding out about it, declared it to the bank the following day.

As a result of this declaration, an internal investigation found last month that he had not broken any formal rules.

The trade was nonetheless “sensitive”, the report added, given, three weeks later, the bank increased franc liquidity and pegged the currency at €1.20. That helped increase the value of other major currencies, including the US dollar, against the franc.

Shares in major Swiss companies fell on yesterday’s resignation news, lead by Novartis, UBS and Crédit Suisse. The Swiss stock market index was down 0.3 per cent in trading yesterday.

After declining to stand down last week, Mr Hildebrand said yesterday his continued presence was a burden on the central bank where he has worked since 2003 and as bank chief since 2010.

The central bank has announced an investigation of the financial affairs of all its top officials.

Meanwhile the whistleblower in the Hildebrand affair, a computer specialist at the bank, was taken to hospital after attempting to take his life.

The 39-year-old employee was said to be in a “unstable mental condition”, a Swiss Sunday newspaper reported, after he was fired by the institution for breaching banking confidentiality rules.

The employee passed information about the trades to officials from the right-wing populist Swiss People’s Party.