Credit Suisse, the investment bank that employs thousands of people in its London headquarters at Canary Wharf, welcomed moves by the Swiss authorities to support the banking system.

But because it has a "relatively low level of affected assets in its portfolio" and "good access to capital markets" it said it would not take up the Swiss National Bank's offer of transferring toxic loans and investments to the central bank.

The decision bears distinct similarities to that of Barclays in the UK, which unlike its rivals Royal Bank of Scotland, Lloyds TSB and HBOS chose to avoid part-nationalisation on Monday.

Like Barclays, Credit Suisse plans to raise fresh capital from private investors, the largest of these as with Barclays being the Qatari Investment Authority. Credit Suisse is one of Barclays' main financial advisers and stockbroker.

Credit Suisse said it will raise just over Swfr10 billion (£5 billion) in new capital. A total of Swfr3.2 billion will come via the sale of ordinary shares, a sale of convertible bonds will produce Swfr1.7 billion with Swfr 5.5 billion from an issue of hybrid tier one capital, a cross between equity and debt paying interest of between 10% and 11% without diluting existing shareholders.

The bank said this would mean its capital requirements would be ahead of the Swiss authorities' targets for 2013.It expects to make a third-quarter loss of Swfr1.3 billion after a further Swfr2.4 billion writedown on its leveraged finance and structured products business.

It said it saw "exceptionally adverse trading conditions in September".

Chief executive Brady Dougan said: "Over the past few months we have had a constructive and close dialogue with regualtors about future capital requirements. I am delighted that our close relationships with a number of strategic investors, who have confidence in our clear strategy and solid business model, have enabled us to raise the necessary capital."

Credit Suisse had losses and writedowns of $10.2 billion (£5.8 billion) in the credit crunch.