17. Other current and non-current assets

Other current liabilities, amounting to €21 million (€71 million at 31 December 2015), and other non-current liabilities, amounting to €309 million (€293 million at 31 December 2015), break down as follows:

Liabilities from regulated activities, amounting to €179 million (€206 million at 31 December 2015), relate to:

• the transportation segment (€141 million) due to the transportation revenue invoiced in excess of the restriction established by the regulator and penalties charged to users who exceeded the committed capacity; this amount is to be returned through tariff adjustments pursuant to Resolution 166/05 of the Authority. The current and non-current portions amount to €12 million and €129 million respectively (€57 million and €110 million at 31 December 2015);
• the storage segment (€38 million) due to payments for balancing and stock replenishment, to be returned to service users pursuant to Resolution 50/06 of the Authority. The amount corresponds entirely to the non-current portion (€39 million at 31 December 2015).

Other liabilities of €151 million (€157 million at 31 December 2015) include:

• prepaid revenue and income (€12 million) relating mainly to the current and non-current portion of the prepaid fee for the concession to use fibre-optic cables given to a telecommunications operator (€2 million and €10 million, respectively);
• other liabilities relating mainly to: (i) guarantee deposits paid as collateral by users of the balancing service, pursuant to Resolution ARG/gas 45/11 (€62 million); and (ii) the higher quantities of fuel gas allocated by users in previous years pursuant to Resolution ARG/gas 184/09 compared with the quantities actually used in those years, equalised by reducing the quantities allocated by users (€66 million). The amount corresponds entirely to the non-current portion (€9 million and €53 million respectively for the current and the non-current portions at 31 December 2015).