To estimate the S&P-adjusted FFO-to-debt ratio for Naturgy Energy Group SA for the fiscal year ended December 31, 2022, we follow the workflow steps below.

### Step 1: Identify the Relevant Industry

Naturgy Energy Group SA is a multinational energy company involved in the distribution and supply of natural gas and electricity, as well as power generation. The provided text outlines methodologies for "Regulated Utilities," "Oil And Gas Exploration And Production," "Unregulated Power And Gas," and "Transportation Infrastructure."

Naturgy operates primarily as a utility with significant regulated distribution networks (gas and electricity) in Spain and other regions, alongside unregulated generation and supply activities. The "Regulated Utilities" section notes that for integrated electric/gas utilities, specific adjustments may apply. However, Naturgy is a diversified utility. The "Unregulated Power And Gas" section applies to companies without protective rate regulation. Given Naturgy's significant regulated asset base (distribution networks), it is best classified under the **Regulated Utilities** sector framework, or potentially a hybrid. However, S&P typically treats large integrated European utilities with significant regulated networks under the Regulated Utilities methodology for leverage metrics, often applying the "Medial Volatility" table if they have substantial unregulated exposure, but the core ratio definition remains FFO/Debt. The prompt asks to estimate the ratio based on the provided facts and general S&P guidelines. The standard definition for FFO and Adjusted Debt in the utility sector generally follows the baseline formulas provided, with specific attention to leases and pension adjustments.

### Step 2: Estimate Adjusted EBITDA

The baseline formula is:
`Adjusted_EBITDA = EBITDA + adjustment_leases + nonrecurring_losses - nonrecurring_gains ± other_adjustments`

From the facts:
*   **EBITDA**: The item "Beneficio Bruto De Explotacion Ebitda" for the period 2022-01-01 to 2023-01-01 is **4,954,000,000 EUR**.

*   **Lease Adjustment**: S&P often adds back the interest portion of lease liabilities or adjusts EBITDA to be pre-lease. However, the standard FFO calculation for utilities often starts with EBITDA and subtracts cash interest. A common adjustment in S&P methodology for "Adjusted EBITDA" in the context of FFO calculation is to ensure consistency with the debt definition. If we use the standard S&P definition for Utilities, FFO is often derived from Net Income + Depreciation + Amortization + Deferred Taxes + Other Non-Cash Items. Alternatively, `FFO = EBITDA - Cash Interest - Cash Taxes + Other Adjustments`.
    Let's look at the "Adjustments For Reconcile Profit Loss" and other items to verify the EBITDA quality.
    The reported EBITDA is 4,954 million EUR.
    Are there significant non-recurring items? The facts show "Other Gains Losses" of -111 million EUR (a loss). This is likely included in the EBITDA calculation or below it. Usually, EBITDA is operating. "Profit Loss From Operating Activities" is 3,083 million.
    Let's check the reconstruction:
    Operating Profit (3,083) + Depreciation/Amortization (1,532) = 4,615 million.
    The reported EBITDA is 4,954 million. The difference (339 million) might include other operating income/expenses or joint venture results.
    "Other Income" is 183 million. "Miscellaneous Other Operating Expense" is 1,511 million.
    Let's assume the reported "Beneficio Bruto De Explotacion Ebitda" of **4,954,000,000 EUR** is the starting point.
    
    *Non-recurring items*: The prompt does not explicitly identify specific non-recurring gains/losses to adjust. We will assume the reported EBITDA is the base.
    *Leases*: In S&P utility methodology, lease liabilities are often treated as debt. The EBITDA figure usually includes the EBITDA contribution from leased assets. No specific add-back for leases is typically required for EBITDA itself unless we are converting from a non-IFRS measure that deducted lease expenses differently. Under IFRS 16, EBITDA typically includes the depreciation of ROU assets and excludes the interest on lease liabilities. The reported EBITDA is likely IFRS 16 compliant. We will use **4,954,000,000 EUR**.

### Step 3: Estimate FFO

The baseline formula provided is:
`FFO = Adjusted_EBITDA - cash_interest - cash_taxes`

*   **Adjusted_EBITDA**: 4,954,000,000 EUR.

*   **Cash Interest**:
    We need the cash interest paid. The facts provide:
    "Interest Paid Classified As Operating Activities": **520,000,000 EUR**.
    "Interest Received Classified As Operating Activities": 87,000,000 EUR.
    S&P typically uses net cash interest paid or gross cash interest paid depending on the specific sector nuance. For utilities, it is often gross interest paid minus interest capitalized or plus/minus derivatives. However, the simplest proxy from the cash flow statement is "Interest Paid".
    Note: "Finance Costs" in the P&L is 837,000,000 EUR. The cash paid is 520,000,000 EUR. The difference is due to accruals, capitalization, or non-cash items. S&P FFO uses **cash** interest.
    So, Cash Interest = **520,000,000 EUR**.

*   **Cash Taxes**:
    The facts provide:
    "Income Taxes Paid Classified As Operating Activities": **762,000,000 EUR**.
    So, Cash Taxes = **762,000,000 EUR**.

*   **Other Adjustments to FFO**:
    Standard S&P FFO also adds back deferred taxes and changes in working capital are *not* added back (they are part of the cash flow). Wait, the formula `FFO = EBITDA - Cash Interest - Cash Taxes` is a simplified cash-flow based proxy.
    Let's verify with the indirect method from Net Income if possible, or stick to the provided formula.
    The prompt explicitly gives the formula: `FFO = Adjusted_EBITDA - cash_interest - cash_taxes`.
    
    Calculation:
    FFO = 4,954,000,000 - 520,000,000 - 762,000,000
    FFO = 3,672,000,000 EUR.

    *Self-Correction/Refinement*: Does S&P adjust for minority interests? FFO is typically funds from operations attributable to the parent. The EBITDA is consolidated. The cash taxes and interest are consolidated.
    Usually, S&P calculates FFO as: Net Income + Depreciation + Amortization + Deferred Taxes + Other Non-Cash Items.
    Let's try calculating FFO using the Net Income approach to see if it aligns, as the EBITDA formula might be too simplistic if it ignores changes in working capital or other operating cash flow items that aren't interest/tax.
    
    Alternative FFO Calculation (Standard S&P):
    Net Income (Profit Loss): 1,826,000,000 EUR.
    Add: Depreciation & Amortization: 1,532,000,000 EUR.
    Add: Deferred Taxes? The P&L shows "Income Tax Expense" of 697 million. Cash Tax is 762 million. Deferred tax expense is roughly Current Tax Expense vs Cash.
    Change in Deferred Tax Liabilities/Assets:
    DTL 2022: 1,787 -> 1,951 (Increase 164).
    DTA 2022: 2,267 -> 2,210 (Decrease 57).
    Net Deferred Tax Liability Increase = 164 + 57 = 221 million. This is a source of cash (add back to Net Income).
    Add: Minority Interest? S&P FFO is usually pre-minority interest for the group leverage, or attributable to parent? S&P ratios usually use Group FFO / Group Debt.
    Let's stick to the prompt's explicit formula: `FFO = Adjusted_EBITDA - cash_interest - cash_taxes`.
    
    FFO = 4,954 - 520 - 762 = **3,672 million 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**:
    We need to sum interest-bearing debt.
    From the Balance Sheet (2022-01-01 to 2023-01-01, we use the ending balance 2023-01-01 for the ratio at year-end 2022):
    
    Noncurrent Financial Liabilities: 13,999,000,000 EUR.
    Breakdown:
    - Longterm Borrowings: 12,689,000,000 EUR.
    - Noncurrent Lease Liabilities: 1,309,000,000 EUR.
    - Other Noncurrent Financial Liabilities: 1,000,000 EUR.
    
    Current Financial Liabilities: 2,302,000,000 EUR.
    Breakdown:
    - Current Borrowings And Current Portion Of Noncurrent Borrowings: 2,110,000,000 EUR.
    - Current Lease Liabilities: 177,000,000 EUR.
    - Other Current Financial Liabilities: 15,000,000 EUR.

    Total Reported Interest-Bearing Debt (Gross Debt) = 
    (12,689 + 1,309 + 0.001) + (2,110 + 0.177 + 0.015)
    = 13,998.001 + 2,287.015
    = **16,285.016 million EUR**.
    Let's use the aggregate "Noncurrent Financial Liabilities" (13,999) and "Current Financial Liabilities" (2,302).
    Total Financial Liabilities = 13,999 + 2,302 = **16,301 million EUR**.
    (Note: The sum of components 12689+1309+1+2110+177+15 = 16,301. Matches.)

*   **Leases**:
    Lease liabilities are already included in "Financial Liabilities" under IFRS 16.
    Noncurrent Lease Liabilities: 1,309 million.
    Current Lease Liabilities: 177 million.
    Total Leases = 1,486 million.
    Since they are already in the Financial Liabilities line, we do not add them again. The formula `reported_debt + leases` implies adding leases if they are *not* in reported debt. Under IFRS, they are. So Reported Debt includes Leases.

*   **Pension Deficit**:
    We need to check for a net pension deficit.
    The facts show "Other Noncurrent Nonfinancial Liabilities" and "Noncurrent Provisions".
    "Noncurrent Provisions": 1,656 million.
    "Other Noncurrent Nonfinancial Liabilities": 2,100 million.
    There is no explicit "Net Pension Liability" line item. However, "Defined Benefit Plans" are mentioned in OCI.
    Without a specific pension deficit figure provided in the liabilities, we assume it is either netted within provisions or negligible/not disclosed as a separate debt-like item in this summary. We will assume **0** adjustment for pension deficit unless we can derive it.
    Looking at Equity: "Other Comprehensive Income... Defined Benefit Plans" shows gains/losses.
    Usually, if not explicitly stated as a liability, we might look at "Provisions". But without a breakdown, we cannot confidently add a pension deficit. We will assume **0**.

*   **Hybrid Debt**:
    Naturgy has issued hybrid bonds. Are they in Equity or Debt?
    "Equity" includes "Noncontrolling Interests" and "Equity Attributable To Owners".
    Hybrids are often classified as equity in IFRS but treated as debt by S&P.
    Looking at the Equity section:
    "Issued Capital": 970
    "Share Premium": 3,808
    "Treasury Shares": -201
    "Reservas": 4,871
    "Resultado...": 1,649
    "Otros Componentes...": -2,844
    Total Equity Attributable to Owners: 7,574.
    
    Naturgy typically has hybrid instruments (e.g., perpetual subordinated notes). In many annual reports, these are classified under Equity (often in Reserves or a specific hybrid equity line). If they are in Equity, we must add them to Adjusted Debt.
    The facts do not explicitly list "Hybrid Instruments" in Equity. However, "Reservas" (Reserves) is 4,871 million. This is a large bucket.
    Let's check the change in Equity.
    If hybrids are present, S&P adds them to debt.
    Without explicit data on the value of hybrids classified as equity, we might have to estimate or assume they are included in "Other Noncurrent Financial Liabilities" if classified as debt, or missed if in equity.
    However, looking at "Noncurrent Financial Liabilities", it is 13,999.
    Looking at standard Naturgy capital structure, they have ~2-3 billion in hybrids.
    If we cannot find a specific line item for "Hybrid Equity" or "Perpetual Subordinated Notes" in the Equity breakdown, we might look for clues.
    "Otros Componentes De Patrimonio" is -2,844. This is likely translation reserves and hedging reserves (negative due to hedging losses seen in OCI).
    "Reservas" is 4,871.
    
    Let's look at the "Cash Flows From Financing Activities".
    "Cobros Pagos Por Instrumentos De Patrimonio" (Proceeds/Payments for Equity Instruments): -503 million.
    "Payments To Acquire Or Redeem Entitys Shares": 503 million.
    This suggests share buybacks or similar.
    
    If we assume the provided facts are comprehensive for the calculation, and no specific "Hybrid Equity" line is identified, we might proceed with the financial liabilities only. *However*, S&P methodology *requires* adding hybrids.
    Let's look at "Noncurrent Financial Liabilities" again. 13,999 million.
    Long-term borrowings: 12,689.
    Lease Liabilities: 1,309.
    Other: 1.
    Sum: 13,999.
    
    If hybrids are in Equity, they are not in these numbers.
    If hybrids are in Debt, they are in "Longterm Borrowings" or "Other".
    Given the ambiguity and lack of a specific "Hybrid" line in Equity, we will calculate Adjusted Debt based on the explicit Financial Liabilities. *Note: In a real-world scenario, one would dig into the notes for Hybrids. Based strictly on the provided text, we cannot identify a specific hybrid equity amount to add back. We will assume the "Longterm Borrowings" captures the main debt.*
    
    *Correction*: Often, "Long-term Borrowings" includes hybrids if classified as debt. If classified as equity, they are in Equity. If we miss them, Debt is understated.
    Let's check if there is a "Mezzanine" or similar. No.
    We will proceed with **Total Financial Liabilities** as the base for Debt.
    Total Debt = 16,301 million EUR.

*   **Eligible Cash**:
    S&P deducts cash and cash equivalents from debt.
    "Cash And Cash Equivalents" (2023-01-01): **3,985,000,000 EUR**.
    Are there restrictions? The facts don't specify restricted cash. We assume all is eligible.
    
    Adjusted Debt = Total Financial Liabilities - Cash
    Adjusted Debt = 16,301,000,000 - 3,985,000,000
    Adjusted Debt = **12,316,000,000 EUR**.

    *Refinement on Leases*:
    S&P sometimes treats leases differently. In the "Regulated Utilities" section, it mentions "Accounting characteristics" but doesn't explicitly exclude leases from debt. In fact, for most corporates, S&P includes lease liabilities in debt. Our "Total Financial Liabilities" includes lease liabilities (1,309 + 177 = 1,486). So they are included.

    *Refinement on Hybrids*:
    If we assume standard Naturgy structure, there are hybrids. If we cannot find them, our Debt might be low. However, based *strictly* on the provided facts, we cannot invent a number. We must use the provided numbers. The provided "Longterm Borrowings" is 12,689. "Noncurrent Financial Liabilities" is 13,999.
    
    Let's double check if "Other Noncurrent Financial Liabilities" (1 million) could be hybrids? Unlikely, too small.
    Are hybrids in "Equity"? If so, we are missing them.
    However, often in these simplified fact sets, if it's not broken out, it might be embedded or not required for the specific exercise if the user expects a calculation based *only* on the visible lines.
    
    Let's calculate the ratio with the available data.
    
    FFO = 3,672 million EUR.
    Adjusted Debt = 12,316 million EUR.

### Step 5: Calculate FFO / Adjusted Debt

Ratio = 3,672 / 12,316

Calculation:
3,672 / 12,316 ≈ 0.298148...

Let's review the inputs for potential errors.

1.  **EBITDA**: 4,954.
2.  **Cash Interest**: 520.
3.  **Cash Taxes**: 762.
    FFO = 4,954 - 520 - 762 = 3,672.

4.  **Debt**:
    Noncurrent Financial Liab: 13,999.
    Current Financial Liab: 2,302.
    Total Debt: 16,301.
    Cash: 3,985.
    Net Debt: 12,316.

    Ratio: 3,672 / 12,316 = 0.2981.

    *Alternative Interpretation of FFO*:
    Sometimes S&P FFO adds back "Minority Interest" if the debt is consolidated?
    The formula `FFO = EBITDA - Cash Interest - Cash Taxes` produces a pre-minority interest figure (since EBITDA is consolidated).
    The Debt is consolidated.
    So the ratio is consistent (Group FFO / Group Net Debt).

    *Check for Pension Deficit*:
    If there is a significant pension deficit, it should be added to debt.
    In the OCI, we see "Gains Losses On Remeasurements Of Defined Benefit Plans".
    2022: 97 million (gain) before tax.
    This suggests the plan might be in surplus or the deficit decreased.
    Without a balance sheet line for "Net Pension Liability", we assume it's not a material debt-like item or is included in provisions. Given the gain, it's unlikely to be a large deficit requiring a huge add-back.

    *Check for Hybrids again*:
    If Naturgy has ~2.5B in hybrids classified as equity, the Debt would be 12,316 + 2,500 = 14,816.
    Ratio would be 3,672 / 14,816 = 0.2478.
    However, I cannot assume the 2.5B figure without it being in the text.
    Is there any clue in "Reservas"?
    Reservas 2023: 4,871.
    Reservas 2022: 4,757.
    This includes legal reserves, retained earnings, etc.
    Without a specific label, I will stick to the explicit Financial Liabilities.

    *One more check on Cash Interest*:
    "Finance Costs" = 837.
    "Interest Paid" = 520.
    The difference (317) is significant.
    Why? Capitalized interest? Accruals?
    S&P uses **Cash Interest**. So 520 is correct.

    *One more check on Cash Taxes*:
    "Income Tax Expense" = 697.
    "Income Taxes Paid" = 762.
    S&P uses **Cash Taxes**. So 762 is correct.

    *One more check on EBITDA*:
    Reported EBITDA = 4,954.
    Is this "Adjusted"?
    The line item is "Beneficio Bruto De Explotacion Ebitda". This is typically the standard operating EBITDA.
    S&P might adjust for non-recurring items.
    "Other Gains Losses" = -111.
    "Gains On Disposals" = 8.
    If these are included in EBITDA, and are non-recurring, we should adjust.
    Usually, "Other Gains/Losses" might be below EBITDA or included.
    If included in EBITDA:
    Add back loss of 111?
    Subtract gain of 8?
    Net adjustment: +103.
    Adjusted EBITDA = 4,954 + 103 = 5,057.
    FFO = 5,057 - 520 - 762 = 3,775.
    Ratio = 3,775 / 12,316 = 0.3065.

    However, "Other Gains Losses" is often part of Operating Profit but might be excluded from EBITDA depending on the company's definition.
    Let's check the reconciliation:
    Operating Profit: 3,083.
    Depreciation: 1,532.
    Sum: 4,615.
    EBITDA Reported: 4,954.
    Difference: 339.
    What makes up the 339?
    "Other Income": 183.
    "Miscellaneous Other Operating Expense": -1,511 (This is an expense, so it reduces profit).
    Wait, Operating Profit is after all operating expenses.
    Revenue (33,965) - Raw Materials (27,194) - Employee Benefits (547) - Misc Operating Exp (1,511) - Depreciation (1,532) + Other Income (183) + Gov Grants (50) + Gains on Disposal (8) - Allowance for credit losses (-228, which is a gain/reduction in expense?) + Other Gains/Losses (-111).
    
    Let's reconstruct Operating Profit:
    33,965 - 27,194 - 547 - 1,511 - 1,532 + 183 + 50 + 8 - 111 + 228 (Allowance decrease is income) = ?
    33,965 - 27,194 = 6,771
    6,771 - 547 = 6,224
    6,224 - 1,511 = 4,713
    4,713 - 1,532 = 3,181
    3,181 + 183 = 3,364
    3,364 + 50 = 3,414
    3,414 + 8 = 3,422
    3,422 - 111 = 3,311
    3,311 + 228 = 3,539.
    
    The reported "Profit Loss From Operating Activities" is 3,083.
    My reconstruction is 3,539. Difference of 456.
    There might be other operating expenses not listed or "Raw Materials" includes more.
    Regardless, the reported EBITDA is 4,954.
    
    If we assume the reported EBITDA is the standard starting point and no specific non-recurring adjustments are identified as *outside* of this figure (or if they are immaterial/not specified as non-recurring in the text), we use 4,954.
    
    Let's stick to the base calculation:
    FFO = 3,672.
    Debt = 12,316.
    Ratio = 0.2981.

    Rounding to four decimal places: 0.2981.

<answer>0.2981</answer>