| Shares
£m | Sundry investments
£m | Total
£m |
|---|
| Cost | | | |
| At 1 January 2013 | 400.0 | 0.6 | 400.6 |
| At 31 December 2013 | 400.0 | 0.6 | 400.6 |
| Provision for impairment | | | |
| At 1 January 2013 | 7.4 | – | 7.4 |
| At 31 December 2013 | 7.4 | – | 7.4 |
| Net book value | | | |
| At 31 December 2013 | 392.6 | 0.6 | 393.2 |
| At 31 December 2012 | 392.6 | 0.6 | 393.2 |
The sundry investments relate to the Bodycote Investment Incentive Plan, as explained in the Board Report on Remuneration.
Details of principal subsidiary undertakings of the Company are shown in Principal subsidiary undertakings.