Step 1: Identify the relevant industry
Italgas S.p.A. is an Italian natural gas distribution company. According to the provided S&P methodology, gas distribution companies fall under the "Regulated Utilities" sector.

Step 2: Estimate Adjusted EBITDA
To calculate Adjusted EBITDA, we start with the reported EBITDA and make necessary adjustments.
From the income statement data:
- Profit Loss From Operating Activities (EBIT) 2022: 641,338,000 EUR
- Depreciation Amortisation And Impairment Loss 2022: 479,186,000 EUR
- Reported EBITDA = EBIT + Depreciation & Amortization = 641,338,000 + 479,186,000 = 1,120,524,000 EUR

S&P adjustments for Regulated Utilities include adding back lease expenses (operating lease adjustments). We use the "Cash Outflow For Leases" from the cash flow statement as a proxy for the lease expense:
- Cash Outflow For Leases: 27,865,000 EUR
- Other normalization adjustments (non-recurring gains/losses): We deduct the "Gains On Change In Fair Value Of Derivatives" which is a non-operating gain already excluded from EBIT but if we reconstruct EBITDA from cash flows or adjust it, we ensure non-recurring items are normalized. The gain of 1,049,000 is already below EBIT, so no further deduction from EBITDA is needed.
- Adjusted EBITDA = 1,120,524,000 + 27,865,000 = 1,148,389,000 EUR

Step 3: Estimate FFO
The baseline formula for FFO is: FFO = Adjusted EBITDA - cash_interest - cash_taxes.
- Cash interest: We use the "Finance Costs Paid Classified As Operating Activities" as reported in the cash flow statement: 53,720,000 EUR.
- Cash taxes: We use the "Income Taxes Paid Classified As Operating Activities": 152,372,000 EUR.
- FFO = 1,148,389,000 - 53,720,000 - 152,372,000 = 942,297,000 EUR

Step 4: Estimate Adjusted Debt
The baseline formula is: Adjusted_Debt = (reported_debt + leases + pension_deficit + guarantees + hybrid_debt_portion + other_debt_like_items) - eligible_cash.
- Reported debt: Sum of short-term and long-term financial liabilities.
  Short Term Financial Liabilities: 142,437,000 EUR
  Long Term Financial Liabilities: 6,402,913,000 EUR
  Total reported debt = 6,545,350,000 EUR
- Leases: We capitalize the operating leases by multiplying the lease expense by a standard factor of 8x (S&P standard multiple for European utilities).
  Leases = 27,865,000 * 8 = 222,920,000 EUR
- Pension deficit: Other Longterm Provisions + Noncurrent Provisions For Employee Benefits = 144,277,000 + 69,917,000 = 204,194,000 EUR
- Eligible cash: For a regulated utility, we net excess cash. We take the closing Cash And Cash Equivalents: 451,946,000 EUR. (S&P methodology mentions adjusting inventory and short-term borrowings for seasonal gas utilities, but the debt already includes short-term borrowings, so we simply net the cash).
- Adjusted Debt = 6,545,350,000 + 222,920,000 + 204,194,000 - 451,946,000 = 6,520,518,000 EUR

Step 5: Calculate FFO / Adjusted Debt
- FFO / Adjusted Debt = 942,297,000 / 6,520,518,000 = 0.144524...

Rounding to four decimal places, the ratio is 0.1445.

<answer>0.1445</answer>