To calculate the S&P-adjusted debt-to-EBITDA ratio for ENI S.P.A. for the fiscal year 2022, we apply the standard S&P Global Ratings corporate methodology, identifying the relevant adjustments for the Oil and Gas Exploration and Production sector.

**Step 1: Estimate Adjusted Debt**
S&P adjusts reported debt to include lease liabilities, post-retirement obligations (pensions), and the debt portion of hybrid securities, while deducting highly liquid accessible cash.

*   **Reported Financial Debt:**
    *   Short-term borrowings: 4,446,000,000 EUR
    *   Current portion of long-term borrowings: 3,097,000,000 EUR
    *   Long-term borrowings: 19,374,000,000 EUR
    *   *Total Reported Debt = 26,917,000,000 EUR*
*   **Lease Liabilities:**
    *   Current lease liabilities: 884,000,000 EUR
    *   Non-current lease liabilities: 4,067,000,000 EUR
    *   *Total Leases = 4,951,000,000 EUR*
*   **Pension Deficit:**
    *   Noncurrent provisions for employee benefits: *786,000,000 EUR*
*   **Hybrid Debt Portion:** 
    *   Eni issued perpetual subordinated bonds accounted for as equity (3,000,000,000 EUR in 2020 and 2,000,000,000 EUR in 2021). S&P assigns these standard corporate hybrids an intermediate equity content, treating them as 50% debt and 50% equity.
    *   *Hybrid Debt Portion = 5,000,000,000 EUR * 50% = 2,500,000,000 EUR*
*   **Eligible Cash & Liquid Investments:**
    *   Cash and cash equivalents: 10,155,000,000 EUR
    *   Current financial assets at fair value through profit or loss (liquid marketable securities): 8,251,000,000 EUR
    *   *Total Eligible Cash = 18,406,000,000 EUR*

*Adjusted Debt = 26,917 + 4,951 + 786 + 2,500 - 18,406 = 16,748,000,000 EUR*

**Step 2: Estimate Adjusted EBITDA**
S&P bases its EBITDA on the company's operating profit, adding back depreciation and amortization, non-recurring item write-offs, and asset impairments. Furthermore, since the share of profit from equity-accounted investments is typically excluded from operating profit, cash dividends received from these joint ventures are added back to reflect the actual cash operating performance.

*   Profit (Loss) from Operating Activities: 17,510,000,000 EUR
*   Depreciation and Amortisation Expense: 7,205,000,000 EUR
*   Impairment Loss Reversal: 1,140,000,000 EUR
*   Write-Off of Tangible and Intangible Assets: 599,000,000 EUR
*   Dividends Received (Classified as Operating Activities): 1,545,000,000 EUR

*Adjusted EBITDA = 17,510 + 7,205 + 1,140 + 599 + 1,545 = 27,999,000,000 EUR*

**Step 3: Calculate the Ratio**
Adjusted Debt / Adjusted EBITDA = 16,748,000,000 EUR / 27,999,000,000 EUR = 0.5981...

<answer>0.60</answer>