22 Short-term debt

The increase in short-term debt of €519 million included net assumptions for €1,029 million, partially offset by foreign currency translation differences of €570 million. Commercial papers of €1,767 million (€1,481 million at December 31, 2012) were issued by the Group’s financial subsidiaries Eni Finance USA Inc (€1,587 million) and Eni Finance International SA (€180 million).

The breakdown by currency of short-term debt is provided below:

At December 31, 2013, the weighted average interest rate on short-term debt was 1.1% (1.5% at December 31, 2012).

At December 31, 2013, Eni had undrawn committed and uncommitted borrowing facilities amounting to €2,141 million and €12,187 million, respectively (€1,241 million and €10,932 million at December 31, 2012). Those facilities bore interest rates reflecting prevailing conditions in the marketplace. Charges for unutilized facilities were immaterial.

At December 31, 2013, Eni was in compliance with covenants and other contractual provisions in relation to borrowing facilities.

The fair value of short-term debt and loans matched their respective carrying amounts considering the short-term maturity.

Payables due to related parties are described in Note 43 – Transactions with related parties.