Step 1 — Relevant industry  
Terna S.p.A. is the Italian national electricity transmission grid operator. This fits the “Regulated Utilities” methodology, specifically an electricity network/transmission utility. The provided methodology indicates that regulated utilities are assessed with sector-specific attention to regulatory frameworks, but the debt-to-EBITDA calculation still follows the corporate ratios-and-adjustments approach unless specific items such as purchased power obligations, securitized debt, or seasonal working capital adjustments apply. No sufficient data for such specific adjustments is provided here.

Step 2 — Estimate Adjusted_Debt  

Use the baseline formula:

Adjusted_Debt = reported_debt + leases + pension_deficit + guarantees + hybrid_debt_portion + other_debt_like_items − eligible_cash

Reported debt at 2022 year-end / 2023-01-01:
- Long-term borrowings: EUR 8,416.7m
- Short-term borrowings: EUR 444.1m
- Current portion of long-term borrowings: EUR 1,909.3m

Reported debt = 8,416.7 + 444.1 + 1,909.3 = EUR 10,770.1m

Hybrid debt adjustment:
- Terna issued perpetual hybrid bonds recorded in equity: EUR 989.0m
- Under S&P-style treatment, hybrids commonly receive partial equity credit. A typical estimate is 50% debt / 50% equity when no more detailed instrument terms are provided.
- Hybrid debt portion = 50% × 989.0 = EUR 494.5m

Pension deficit:
- Noncurrent provisions for employee benefits: EUR 48.4m
- This is treated as debt-like in this estimate.
- Pension adjustment = EUR 48.4m

Leases, guarantees, and other debt-like items:
- Not separately provided, so estimated as EUR 0.

Eligible cash:
- Cash and cash equivalents: EUR 2,155.1m
- In the absence of restricted-cash details or S&P surplus-cash haircuts, use reported cash as eligible cash.

Adjusted_Debt = 10,770.1 + 494.5 + 48.4 − 2,155.1 = EUR 9,157.9m

Step 3 — Estimate Adjusted_EBITDA  

Reconstruct EBITDA from operating profit plus depreciation/amortization/impairment:

- Profit from operating activities / EBIT: EUR 1,333.5m
- Depreciation, amortisation and impairment: EUR 725.7m

EBITDA = 1,333.5 + 725.7 = EUR 2,059.2m

No clear lease, pension service-cost, JV proportional EBITDA, or nonrecurring normalization adjustment is available from the provided facts. The discontinued operations loss is below operating profit and not included in this EBITDA reconstruction.

Adjusted_EBITDA ≈ EUR 2,059.2m

Step 4 — Adjusted_Debt / Adjusted_EBITDA  

Adjusted_Debt / Adjusted_EBITDA = 9,157.9 / 2,059.2 = 4.4473

Rounded to two decimals = 4.45

<answer>4.45</answer>