Derivative financial assets and available for sale investments
2011 £m 
2010 £m 

Available for sale investments – Unlisted ordinary shares  7.6  7.8 
Derivative financial instruments – Interest rate derivatives  23.7  – 
Derivative financial instruments – Fuel derivatives  7.3  7.2 
Derivative financial instruments included in noncurrent assets  31.0  7.2 
Derivative financial instruments – Interest rate derivatives  –  3.8 
Derivative financial instruments – Fuel derivatives  13.1  14.1 
Derivative financial instruments – Foreign exchange derivatives  8.0  0.4 
Derivative financial instruments included in current assets  21.1  18.3 
Further information on the Group's use of fuel, interest rate and foreign exchange derivatives is included in note 31.
Available for sale investments
2011 £m 
2010 £m 

Cost or valuation and net book value:  
At 1 January  7.8  7.7 
Additions  –  0.3 
Foreign exchange  (0.2)  (0.2) 
At 31 December  7.6  7.8 
The principal available for sale investments are as follows:
2011  2010  
Name  Country of registration  Class of share  Proportion held % 
Proportion held % 
Bosnjak Holdings Pty Ltd  Australia  Ordinary shares  86  86 
Prepayment Cards Limited (PCL)  England and Wales  Ordinary shares  –  23.5 
Metros Ligeros de Madrid, S.A. (MLM)  Spain  Ordinary shares  15  15 
Various investments within ALSA and Continental Auto  Spain  Ordinary shares  116  116 