To compute Net Debt/EBITDA for ERG S.p.A. for FY 2022 (period ending 2023‑01‑01) under S&P’s methodology I first identified the debt components and cash equivalents at year‑end.

**Debt (interest‑bearing)**
- Other non‑current financial liabilities: 1,751,255 k€
- Non‑current lease liabilities: 150,955 k€
- Other current financial liabilities: 389,716 k€
- Current lease liabilities: 6,362 k€  

Total debt = 1,751,255 + 150,955 + 389,716 + 6,362 = 2,298,288 k€.

**Cash & equivalents**
- Cash and cash equivalents: 392,811 k€
- Current financial assets at fair value through P&L (short‑term, liquid): 141,568 k€  

Cash = 392,811 + 141,568 = 534,379 k€.

**Net Debt**
Net Debt = Total Debt – Cash = 2,298,288 – 534,379 = 1,763,909 k€.

**EBITDA**
The figure “Profit loss from operating activities before interest, taxes, depreciation and amortisation expense” for 2022 is 499,430 k€, which corresponds to EBITDA under S&P’s definition.

**Ratio**
Net Debt / EBITDA = 1,763,909 / 499,430 ≈ 3.53.

Thus, the Net Debt/EBITDA ratio for 2022 is approximately **3.5**.

<answer>3.53</answer>