Step 1: Identify the relevant industry
Terna S.p.A. is the Italian electricity transmission grid operator, which makes it a Regulated Utility. Based on the provided methodologies, we will follow the "Regulated Utilities" methodology.

Step 2: Estimate Adjusted EBITDA
Under S&P guidelines, we start with reported EBITDA and make standard adjustments. 
From the income statement data:
- Profit Loss From Operating Activities (EBIT) = 1,333,500,000 EUR
- Depreciation Amortisation And Impairment Loss Reversal = 725,700,000 EUR
Reported EBITDA = EBIT + Depreciation/Amortisation = 1,333,500,000 + 725,700,000 = 2,059,200,000 EUR.

We check for lease adjustments. Finance Costs are 121,800,000 EUR. Given the nature of the utility and no explicit lease data in the facts, the interest component of operating leases is typically estimated around 25-30% of the rent expense. Rent is usually in "Services Expense" or "Other Expense". Even assuming a maximum typical adjustment, it is relatively small. For Regulated Utilities, lease adjustments often use a 6x multiplier on the estimated interest. However, lacking specific lease details, a standard baseline assumes minimal to no material lease adjustments unless substantial operating leases are identified. We will also evaluate hybrid debt interest as a potential subtrahend from FFO later, but not from EBITDA. 
Adjusted EBITDA = 2,059,200,000 EUR.

Step 3: Estimate FFO
The S&P baseline formula for FFO is: FFO = Adjusted EBITDA - cash_interest - cash_taxes.
- Cash interest: We use "Interest Paid Classified As Operating Activities" = 154,800,000 EUR. (Note: Hybrid bond coupons of 21,100,000 EUR are treated as distributions/equity-like by S&P for Regulated Utilities, so they are deducted from FFO but not treated as debt interest; they are already excluded from the 154.8m reported interest paid).
- Cash taxes: We use "Income Taxes Paid Refund Classified As Operating Activities" = 380,100,000 EUR.
FFO = 2,059,200,000 - 154,800,000 - 380,100,000 = 1,524,300,000 EUR.

Step 4: Estimate Adjusted Debt
Under S&P guidelines for Regulated Utilities, Adjusted Debt = Reported Debt + Leases + Pension Deficit + Hybrid Debt - Eligible Cash.
- Reported Debt (Short-term + Long-term + Current portion of Long-term):
  Shortterm Borrowings (2022-12-31) = 1,947,000,000 EUR
  Current Portion Of Longterm Borrowings = 1,640,000,000 EUR
  Longterm Borrowings = 8,835,000,000 EUR
  Total Reported Debt = 1,947,000,000 + 1,640,000,000 + 8,835,000,000 = 12,422,000,000 EUR.
- Leases: As calculated in Step 2, no material lease addition is identified.
- Pension Deficit: Noncurrent Provisions For Employee Benefits = 60,800,000 EUR. Net liability is small relative to debt, but we add it: +60,800,000 EUR.
- Hybrid Debt: Terna has hybrid perpetual bonds classified as equity under IFRS ("Equity Instruments Perpetual Hybrid Bonds" = 989,000,000 EUR). S&P typically treats hybrid bonds as 100% debt if there is step-up or limited permanence, or 50% if intermediate. In baseline calculations lacking specific step-up details, 50% is the standard conservative approach for intermediate equity content, but for many European utilities with standard step-ups, 100% is applied. We'll apply the standard 50% equity credit assumption: +494,500,000 EUR.
- Eligible Cash: Cash And Cash Equivalents = 1,566,800,000 EUR.

Adjusted Debt = 12,422,000,000 + 60,800,000 + 494,500,000 - 1,566,800,000 = 11,410,500,000 EUR.

Step 5: Calculate FFO / Adjusted Debt
FFO / Adjusted Debt = 1,524,300,000 / 11,410,500,000 = 0.13358448...

Rounding to four decimal places:
0.1336

<answer>0.1336</answer>