180,000 members secured by insurance companies

The consultant said up to one million members could be part of de-risked schemes by end of 2009.

It said it expected the buyout market to grow to around £12bn this year – and said the size of buy-ins and buyouts would continue to increase significantly.

HSBC Actuaries & Consultants head of corporate consulting Jonathan Sarkar said: "This shows the growth and potential of the nascent buyout market.

"The increase in insurers’ appetite to take on longevity and sponsor risk means that that there is now a wide range of solutions available to companies wishing to transfer liabilities away from a final salary pension scheme.

"The traditional ‘buy-out’ is now simply not innovative enough for most plan sponsors."