I need to analyze VINCI's financial position to determine the optimal utilization of hybrid bonds relative to S&P Global Ratings' 15% cap on equity credit from hybrids.

## Key Financial Data Analysis

First, let me extract VINCI's capital structure at end of 2022:

**Equity:**
- Total Equity: €29,409 million (2023-01-01) / €24,771 million (2022-01-01)
- Equity Attributable to Owners of Parent: €25,939 million
- Noncontrolling Interests: €3,470 million

**Debt/Liabilities:**
- Noncurrent Liabilities: €34,316 million
- Current Liabilities: €47,939 million
- Total Liabilities: €82,255 million

However, I need to focus on **adjusted capital** = debt + equity for the S&P methodology.

Let me calculate total capital more carefully. S&P's "adjusted capital" typically means:
- Equity (including hybrid equity credit)
- Plus debt

From the balance sheet:
- Total Equity at 2022 year-end: €29,409 million
- Total Liabilities: €82,255 million

But we need to distinguish debt from other liabilities. Looking at key debt items:
- Noncurrent Portion of Noncurrent Bonds Issued: €20,425 million
- Noncurrent Portion of Other Noncurrent Borrowings: €3,205 million
- Short-term Borrowings: €6,368 million
- Current Lease Liabilities: €522 million
- Noncurrent Lease Liabilities: €1,580 million

Rough debt estimate: €20,425 + €3,205 + €6,368 + €522 + €1,580 ≈ €32,100 million

However, for S&P's total adjusted capital, we typically use:
- Total Equity: €29,409 million
- Plus total debt (financial debt): approximately €30,000-32,000 million

Total Adjusted Capital ≈ €29,409m + €32,000m ≈ €61,409 million

The 15% cap on hybrid equity credit means:
- Maximum equity credit from hybrids = 15% × €61,409m ≈ €9,211 million

This means hybrid bonds could represent up to approximately:
- €9,211m / €32,000m ≈ 28.8% of total debt capacity could be in hybrid form with full equity credit

But the question asks about **utilization relative to the cap** - i.e., should they use 0%, 25%, 50%, 75%, or 100% of the 15% cap?

## Analysis of VINCI's Suitability for Hybrids

**Factors supporting hybrid bond usage:**

1. **Strong credit profile needed for hybrid equity credit**: VINCI has:
   - Strong profitability: Operating profit €6,489m in 2022 vs €4,438m in 2021 (46% increase)
   - Net profit: €4,417m in 2022 vs €2,195m in 2021 (more than doubled)
   - Strong cash flow: Operating cash flow €9,387m
   - Solid interest coverage with Net Finance Costs of €614m

2. **Business model characteristics**:
   - Infrastructure/concession business with long-term, stable cash flows
   - Hybrid bonds are particularly suitable for companies with predictable, long-duration cash flows
   - Concession activities (€28.2bn service concession rights) provide annuity-like revenues

3. **Current leverage position**: 
   - Equity/Assets ratio: €29,409m/€111,991m = 26.3% - moderate leverage
   - Room to add leverage while maintaining investment grade

4. **Market conditions in 2022**:
   - Rising interest rate environment (5Y swap went from -0.264% to 1.726%)
   - Corporate bond spreads widened (iBoxx non-financial IG at 2.295%)
   - Hybrids become relatively more attractive in higher rate environments

5. **Strategic benefits of hybrids**:
   - Equity credit improves leverage ratios without diluting shareholders
   - Lower cost than pure equity
   - Tax deductibility of interest (though this varies by jurisdiction)

**Factors limiting hybrid usage:**

1. **Already strong equity base**: €29.4bn equity is substantial
2. **No immediate distress**: Company is profitable and growing
3. **Complexity and cost**: Hybrids are more expensive than senior debt

## Optimal Utilization Assessment

Given VINCI's profile:
- Strong, stable cash flows from concessions (ideal for hybrid servicing)
- Moderate leverage with room to optimize capital structure
- Investment grade credit quality expected
- Need to balance equity credit benefits with cost

For a company like VINCI with:
- Stable, long-term cash flows
- Infrastructure/concession characteristics
- Strong profitability and cash generation
- Moderate current leverage

The optimal strategy would be to **meaningfully utilize** the hybrid capacity but perhaps not maximize it, because:
- Full 100% utilization might signal leverage concerns to markets
- 0% or 25% would underutilize a valuable financial tool for this business model
- 75-100% might be aggressive given they don't have urgent balance sheet repair needs

**50% utilization** of the 15% cap appears optimal because:
- It provides meaningful equity credit improvement (7.5% of adjusted capital)
- It's a prudent, balanced approach for a healthy company
- It leaves headroom for future flexibility
- Matches the "hybrid" nature of these instruments - use them as a tool, not a crutch
- For a BBB+/A- type credit, this is consistent with market practice

Companies with more pressing leverage concerns or lower ratings might need 75-100%, while those with very conservative policies might use 25%. VINCI's strong 2022 performance suggests they don't need maximum hybrid utilization, but their concession-based business model strongly supports using them at a moderate level.

<answer>50%</answer>