11 Other financial assets 31.12.2009 31.12.2010
  CHF thousands    
  Prepaid green electricity certificates 10,402 5,768
  Prepaid long – term electricity procurement agreements 53,170 50,040
  Other non – current securities 7,276 7,592
  Total 70,848 63,400

Prepayments for green electricity certificates were initially recognised under “fair value through profit or loss”. The fair value of prepaid green electricity certificates is determined using a valuation model which takes into account current third-party selling prices as well as expected future price developments. Prepayments for long-term electricity procurement agreements are amortised on the basis of the physical delivery of electricity and held solely for this purpose. All other financial securities in non-current assets are classified as “available for sale” and recognised at fair value. This does not affect listed shares or equity securities for which there is no active market and hence for which the fair value cannot be reliably determined. The fair value corresponds to the acquisition value less impairments.