Step 1 — Relevant industry

ENGIE is a large integrated energy utility with regulated networks, renewables, thermal generation, energy management, retail supply, and some gas-related activities. Among the provided methodologies, the closest fit is a mix of:

- Regulated Utilities, for networks and regulated energy infrastructure;
- Unregulated Power and Gas, for generation, supply, energy management and merchant/contracted activities.

Because the information provided is consolidated and does not split regulated vs. unregulated EBITDA, I apply the general S&P-style corporate baseline formulas, with utility-relevant judgment where possible.

Step 2 — Estimate Adjusted_Debt

Baseline formula:

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

Available debt data at 2023-01-01:

- Long-term borrowings = €28.083bn
- Current borrowings and current portion of noncurrent borrowings = €12.508bn

Reported debt:

28.083 + 12.508 = €40.591bn

Cash and cash equivalents:

- Cash and cash equivalents = €15.570bn

S&P generally applies surplus/eligible cash netting, but full cash netting may overstate credit benefit for an operating utility. However, the prompt provides no restricted cash or minimum cash detail, so I use reported cash as eligible cash.

Hybrid debt portion:

ENGIE reports deeply subordinated perpetual notes in equity:

- Deeply subordinated perpetual notes = €3.393bn

S&P commonly gives intermediate equity credit to hybrids, often treating 50% as debt and 50% as equity when eligible. Therefore:

Hybrid debt portion = 50% × 3.393 = €1.697bn

Leases, guarantees, pension deficit, and other debt-like items:

- No explicit lease liability amount is provided.
- No pension deficit balance is provided.
- No guarantees or other debt-like items are quantified.

So these are assumed to be zero for this estimate.

Adjusted_Debt:

40.591 + 1.697 - 15.570 = €26.718bn

Step 3 — Estimate Adjusted_EBITDA

A practical EBITDA reconstruction from operating profit:

Profit/loss from operating activities = €1.127bn  
Add depreciation, amortization and provisions = €5.187bn

Basic reconstructed EBITDA:

1.127 + 5.187 = €6.314bn

However, operating profit includes significant nonrecurring and noncash effects. S&P-adjusted EBITDA typically normalizes material nonrecurring losses/gains.

Relevant items:

- Impairment loss / reversal of impairment loss recognized in profit or loss = €2.774bn expense
- Expense of restructuring activities = €0.230bn expense
- Other income/expense from subsidiaries, jointly controlled entities and associates = €0.091bn gain/income
- Other nonrecurring items = -€1.328bn, interpreted as a nonrecurring loss/expense

Normalize EBITDA:

Add back nonrecurring losses:
- Impairment = €2.774bn
- Restructuring = €0.230bn
- Other nonrecurring items loss = €1.328bn

Subtract nonrecurring gains:
- Other income/expense from subsidiaries, JVs and associates = €0.091bn

Adjusted_EBITDA estimate:

6.314 + 2.774 + 0.230 + 1.328 - 0.091 = €10.555bn

Cross-check:

Current operating income including operating MtM = €4.309bn.  
Adding D&A/provisions of €5.187bn gives €9.496bn.  
Adding share of profit from equity-accounted entities of €1.059bn gives €10.555bn.

This matches the normalized EBITDA estimate above, so €10.555bn is a reasonable estimate.

Step 4 — Adjusted_Debt / Adjusted_EBITDA

Adjusted_Debt = €26.718bn  
Adjusted_EBITDA = €10.555bn

Ratio:

26.718 / 10.555 = 2.5313

Rounded to two decimals:

<answer>2.53</answer>