Barclays will not need to raise new capital for at least six months, Bob Diamond, the bank's president, said last night.

Mr Diamond, who runs Barclays Capital, the investment banking division, said he was confident that the bank had enough capital to withstand the deteriorating economy.

The timescale outlined by Mr Diamond is significant. If Barclays raises fresh capital before June, its backers from Abu Dhabi and Qatar would be entitled to receive a greater number of shares for the £7.3 billion investment they made last year without needing to stump up more cash.

The news came as Barclays confirmed that CVC Capital Partners, the private equity group, was the bank's preferred bidder for its iShares exchange-traded funds business.

CVC, whose other assets include holdings in AA Saga, Formula One and Samsonite, the luggage maker, has been given exclusive rights to negotiate and a £3 billion sale is expected within days.

Not included in the deal is the iShares securities lending business, the offshoot that lends shares to short-sellers and other clients, which had deterred private equity buyers because of the extra regulatory requirements it carried. The business could have raised a further £1.4 billion for Barclays had it been sold.

The sale is expected to be part-funded by a loan from Barclays itself. The bank will also receive warrants worth a fifth of the equity of iShares, giving Barclays a share of the upside should the business increase in value.

The price, although falling short of initial expectations of as much as £4 billion, still puts the fast-growing business on a multiple of ten times earnings before interest, tax, depreciation and amortisation.

Funds raised from the sale will be put towards bolstering Barclays' financial strength. The bank's Tier 1 capital ratio, a key measure of capital held on the balance sheet as a proportion of a bank's loan book, stands at only 6.7 per cent - well below that of rivals such as Royal Bank of Scotland and Lloyds Banking Group. This is likely to rise to about 7.2 per cent after the deal.

Mr Diamond said that the decision had been a tough one. He told CNBC: “This has been a very, very difficult decision for us in Barclays - it's an unbelievable business, iShares. We've grown it from a baby.”

CVC, which raised a £10.2 billion fund last year, is understood to have beaten off competition from two rival private equity consortiums. One of these comprised Bain Capital and Colony Capital; the other was made up of Hellman & Friedman - the owner of City fund manager Gartmore - and Apax Partners.

IShares, which at the end of last year had £226 billion under management, is the world's biggest manager of exchange-traded funds - a basket of stocks that can be bought and sold like shares.

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