Pension obligation risk

The Group is also exposed to risk from its defined benefit pension schemes. The schemes' assets comprise investment portfolios which are held to meet projected liabilities to the scheme members. Risk arises from the schemes because returns from these portfolios may be less than expected and because there may be greater than expected increases in the estimated value of the schemes' liabilities. In these circumstances, the Group could be obliged, or may choose, to make additional contributions to the schemes.