I need to analyze whether Ferrovial should utilize hybrid bonds relative to S&P's 15% equity credit cap on hybrids.

Let me first understand the company's financial position and capital structure.

**Key Financial Metrics:**

1. **Existing Hybrid Bonds:** The company already has perpetual subordinated bonds. Looking at the equity section, "Other Equity Securities" is €508M (2023) and €507M (2022), which likely represents existing hybrid/perpetual subordinated bonds classified as equity.

2. **Total Debt:**
   - Noncurrent borrowings: €10,776M
   - Current borrowings: €877M
   - Noncurrent lease liabilities: €120M
   - Current lease liabilities: €64M
   - Other noncurrent financial liabilities: €838M
   - Total debt ≈ €12,675M (rough estimate)

3. **Total Equity:** €6,354M

4. **Total Adjusted Capital (Debt + Equity):** Approximately €12,675M + €6,354M ≈ €19,029M

5. **S&P's 15% cap:** 15% × €19,029M ≈ €2,854M maximum equity credit from hybrids

6. **Current hybrid usage:** ~€508M in perpetual subordinated bonds, which is well below the €2,854M cap (~18% of the cap utilized).

**Considerations for hybrid utilization:**

1. **Leverage:** The company has significant debt, particularly infrastructure project debt (€7,893M noncurrent + €74M current). The debt-to-equity ratio is high (~2:1), suggesting the company could benefit from equity credit to improve credit metrics.

2. **Infrastructure business model:** Ferrovial is a major infrastructure/concessions company with long-duration assets and predictable cash flows from toll roads. This supports the use of hybrid instruments to optimize the capital structure.

3. **Interest rate environment:** The sharp rise in swap rates from negative territory in 2020-2021 to ~1.7-1.9% in 2022 makes hybrid issuance more expensive, but corporate bond spreads (iShares Core Euro Corp Bond at ~1.085%) remain manageable.

4. **Cash flow generation:** Operating cash flows of €1,002M are solid, and the company generates meaningful dividends from associates (€284M).

5. **Non-controlling interests:** Significant at €2,241M, indicating substantial minority stakes in subsidiaries.

6. **Current hybrid is small relative to cap:** Only ~€508M vs. potential ~€2,854M cap, meaning there's substantial room to issue more.

7. **Investment needs:** The company is actively investing in infrastructure projects (-€784M in 2022) and associates (-€347M), suggesting ongoing capital needs.

8. **Credit considerations:** With high leverage from infrastructure project debt (much of which is non-recourse), getting equity credit from hybrids could meaningfully improve corporate-level credit metrics.

**Assessment:**

The company already uses hybrids but at a very low level relative to the S&P cap. Given:
- High leverage requiring credit metric improvement
- Strong, predictable infrastructure cash flows supporting hybrid coupon payments
- Active investment program requiring capital
- The infrastructure business model where rating agencies give some benefit for non-recourse project debt
- Rising rates making pure equity issuance dilutive
- The company is already familiar with hybrid instruments

However, there are some limiting factors:
- Rising interest rates increase hybrid coupon costs
- The company already has substantial project-level debt
- Non-controlling interests are growing, suggesting the company also uses project-level equity partners

Given the infrastructure-heavy business model with long-duration assets, significant capital needs, and existing but modest hybrid usage, I'd expect the company to utilize a moderate-to-significant portion of the S&P hybrid cap. The company has clear incentives to use hybrids for equity credit but the rising rate environment and already elevated leverage suggest not pushing to the full cap.

A 50% utilization seems appropriate - enough to benefit from equity credit while maintaining financial flexibility and not over-relying on hybrid instruments.

<answer>50%</answer>