The BT Pension Scheme, the UK's biggest with almost £40bn (€53bn) in assets, has put in place a hedging strategy insuring a fifth of its equity exposure against stock market falls - a strategy which is still comparatively rare among UK retirement funds.

Nigel Labram, head of pensions management at Hermes, the asset manager for the scheme, said: "We have been diversifying our equities exposure through investments in alternative assets, like private equity and commodities, in recent years.