14 Other current assets

Derivative fair values were estimated on the basis of market quotations provided by primary info-provider, or alternatively, appropriate valuation methods commonly used in the marketplace.

Fair value of cash flow hedge derivatives of €14 million (€31 million at December 31, 2012) of the hedges entered by the Gas & Power segment. These derivatives were entered into to hedge variability in future cash flows associated to highly probable future sale transactions of gas or electricity or on already contracted sales due to different indexation mechanism of supply costs versus selling prices. A similar scheme applies to exchange rate hedging derivatives. Negative fair value of contracts expiring by 2014 is disclosed in Note 26 – Other current liabilities; positive and negative fair value of contracts expiring beyond 2014 is disclosed in Note 21 – Other non-current receivables and in Note 31 – Other non-current liabilities. The effects of the evaluation at fair value of cash flow hedge derivatives are given in Note 33 – Shareholders’ equity and in Note 37 – Operating expenses. Sale commitments of cash flow hedge derivatives amounted to €505 million (purchase and sale commitments of €31 million and €510 million, respectively, at December 31, 2012). Information on hedged risks and hedging policies is disclosed in Note 35 – Guarantees, commitments and risks – Risk factors.

The fair value of other derivative contracts is presented below:

Fair value of other derivatives of €718 million (€916 million at December 31, 2012) consisted of: (i) €369 million (€564 million at December 31, 2012) of derivatives that failed to meet the formal criteria to be designated as hedges under IFRS because they were entered into in order to manage net exposures to movements in foreign currencies, interest rates or commodity prices. Therefore, such derivatives were not related to specific trade or financing transactions; (ii) €344 million (€352 million at December 31, 2012) related to commodity derivatives entered by the Gas & Power segment for trading purposes and proprietary trading; (iii) €5 million of derivatives related to net settlement agreements, of which €7 million of negative fair value hedge derivatives.

Other assets amounted to €593 million (€677 million at December 31, 2012) and included: (i) prepayments and accrued income for €108 million (€146 million at December 31, 2012); (ii) prepaid rentals for €63 million (€51 million at December 31, 2012); and (iii) prepaid insurance premiums for €53 million (€49 million at December 31, 2012). Prepayments that were made to gas suppliers upon triggering the take-or-pay clause provided by the relevant long-term supply arrangements and amounting to €129 million as of December 31, 2012 were fully recovered during 2013 through collection of gas.

Transactions with related parties are described in Note 43 – Transactions with related parties.