To estimate the Net Debt / EBITDA ratio for ERG S.P.A. at the end of 2022 based on S&P methodology, I’ll follow these steps:

1. **Calculate EBITDA**  
   From the data, EBITDA for 2022 is directly given as:  
   `Profit Loss From Operating Activities Before Interest Taxes Depreciation And Amortisation Expense` = **€499,430,000**

2. **Calculate Net Debt**  
   S&P’s methodology typically defines net debt as:  
   **Net Debt = Short-term debt + Long-term debt + Lease liabilities - Cash and cash equivalents - Other liquid financial assets (if readily available)**

   From the balance sheet as of 2023-01-01 (which corresponds to the end of 2022):

   - **Cash and cash equivalents** = €392,811,000  
   - **Current financial liabilities at fair value through profit or loss** = €76,644,000  
   - **Other current financial liabilities** = €389,716,000  
   - **Current lease liabilities** = €6,362,000  
   - **Non-current financial liabilities at fair value through profit or loss** = €0  
   - **Other non-current financial liabilities** = €1,751,255,000  
   - **Non-current lease liabilities** = €150,955,000  

   I will include current and non-current financial liabilities (borrowings), lease liabilities, and subtract cash. I’ll also consider current financial assets at fair value through profit or loss (€141,568,000) and other current financial assets (€211,136,000) if they are liquid, but in a conservative S&P-like net debt calculation, only cash is usually subtracted unless these are explicitly specified as cash equivalents.  
   Given the data, I’ll use only cash and cash equivalents as the offset.

   **Total debt-like items:**  
   = €76,644,000 + €389,716,000 + €6,362,000 + €0 + €1,751,255,000 + €150,955,000  
   = **€2,374,932,000**

   **Net Debt** = €2,374,932,000 - €392,811,000 = **€1,982,121,000**

3. **Ratio**  
   Net Debt / EBITDA = €1,982,121,000 / €499,430,000 ≈ **3.97**

<answer>3.97</answer>