To estimate the Funds From Operations (FFO) to Net Debt ratio for A2A S.p.A. at the end of 2022, we first calculate the FFO and the Net Debt from the provided data.

**1. Funds From Operations (FFO)**
A standard definition of FFO is Net Income (Profit Loss) plus non-cash expenses such as Depreciation and Amortization. 
- Profit Loss (2022): 448,000,000 EUR
- Depreciation Expense (2022): 491,000,000 EUR
- Amortisation Expense (2022): 233,000,000 EUR

FFO = 448,000,000 + 491,000,000 + 233,000,000 = 1,172,000,000 EUR.
*(Note: If provisions and writedowns are fully included, FFO could be estimated up to ~1,266 M EUR, but basic Net Income + D&A is the standard unadjusted baseline).*

**2. Net Debt**
Net Debt is typically calculated as Total Short-term and Long-term Financial Liabilities minus Cash and Cash Equivalents.
- Other Noncurrent Financial Liabilities (Long-term Debt): 5,867,000,000 EUR
- Other Current Financial Liabilities (Short-term Debt): 1,022,000,000 EUR
- Cash and Cash Equivalents: 2,584,000,000 EUR

Total Debt = 5,867,000,000 + 1,022,000,000 = 6,889,000,000 EUR
Net Debt = 6,889,000,000 - 2,584,000,000 = 4,305,000,000 EUR.

**3. FFO / Net Debt Ratio**
FFO / Net Debt = 1,172,000,000 / 4,305,000,000 = 0.2722 (or approx. 27.2%)

<answer>0.272</answer>