Let’s work through the reasoning step-by-step.

**1. Entity profile and sector**
Italgas S.p.A. is a regulated gas distribution utility in Italy. Based on S&P’s methodology for regulated utilities, its business risk is primarily driven by regulatory advantage, scale/scope/diversity, and operating efficiency.

**2. Regulatory environment**
Italy’s regulatory framework for gas distribution is well-established, transparent, and provides cost recovery mechanisms including return on invested capital. This would likely support at least an “adequate” or “strong/adequate” preliminary regulatory advantage.

**3. Financial profile**
From the balance sheet and income statement:
- Total assets grew to ~€11.0bn at end-2022.
- Equity increased to ~€2.39bn.
- Operating profit is stable (€583m -> €641m).
- Net income increased (€362.8m -> €407.3m attributable to parent).
- Significant investment in intangible assets (~€767m in 2022), indicating ongoing capex.
- Cash position dropped sharply (€1.39bn -> €452m), and net debt increased significantly (short-term financial liabilities + long-term: ~€6.4bn -> ~€6.55bn).
- Gross debt/EBITDA is not available but presumably moderate for a regulated utility, though the cash decrease suggests net debt is rising.

**4. Hybrid issuance history**
Italgas has **never** issued hybrid bonds. This strongly signals that it has historically not needed them and that the cost/benefit trade-off has not been favorable.

**5. Current funding and rating considerations**
- There is no acute refinancing pressure; the company generates stable operating cash flows.
- No transformational M&A or extreme capex indicated (capex is ongoing but typical for the sector).
- Equity ratio is adequate for the sector (~22%).
- No indication that the rating is under imminent downgrade pressure requiring hybrid support.

**6. Market conditions in 2022**
- Swap rates rose sharply from negative to ~1.7–1.9% for 5–10Y maturities.
- Subordinated (hybrid) bond yields (sub-sen delta ~0.2% over senior IG) would be around 2.3% average, still elevated versus prior years.
- Issuing a hybrid now would increase average cost of debt, with limited rating benefit.

**7. Guideline mapping**
The case fits best with the **0%** guidance:
- No existing hybrids; no recent issuance.
- No transformational acquisition or extreme capex program.
- Rating likely solid investment grade without hybrid support.
- Cost of hybrid would materially increase current cost of debt.
- No urgent leverage optimization needed.

Therefore, the advisable hybrid issuance level is **0%**.

<answer>0%</answer>