To determine the appropriate extent to which Veolia Environnement should utilize hybrid bonds, we must analyze its current capital structure, recent financial performance, and strategic context against the provided S&P Global Ratings methodology and market conditions.

**1. Current Capital Structure and Hybrid Position**
First, we calculate the "Total Adjusted Capital" to determine the current percentage of hybrid debt.
*   **Equity (2023-01-01):** 14,866.9 million EUR.
*   **Hybrid Debt (Titres Super Subordonnes A Duree Indeterminee):** 3,496.3 million EUR.
*   **Debt Calculation:** To find Total Adjusted Capital (Equity + Adjusted Debt), we need the debt figure.
    *   Noncurrent Financial Liabilities (excluding concession): 19,692.1 million EUR.
    *   Current Financial Liabilities (excluding concession): 6,521.4 million EUR.
    *   Lease Liabilities (Noncurrent + Current): 1,656.2 + 496.5 = 2,152.7 million EUR.
    *   Concession Liabilities (Noncurrent + Current): 1,680.5 + 243.2 = 1,923.7 million EUR.
    *   *Note on Adjustments:* S&P typically treats concession liabilities and lease liabilities as debt-like or adjusts them based on sector specifics. For a utility/infrastructure player like Veolia, concession liabilities are often treated as debt. Let's assume a broad definition of Adjusted Debt includes Financial Liabilities + Leases + Concessions.
    *   Total Debt approx = 19,692.1 + 6,521.4 + 2,152.7 + 1,923.7 = 30,289.9 million EUR.
    *   **Total Adjusted Capital** = Equity (14,866.9) + Adjusted Debt (30,289.9) = ~45,156.8 million EUR.
    *   **Current Hybrid %** = 3,496.3 / 45,156.8 ≈ **7.7%**.

Veolia already has a significant portion of its capital structure in hybrids (~7.7%). The prompt asks for the extent to which the entity *should be advised to issue* hybrid bonds, resulting in a target percentage of total adjusted capital. The options are 0%, 3.75%, 7.5%, 11.25%, and 15%. Since the current level is already ~7.7%, advising a target of 0% or 3.75% would imply a massive redemption of existing hybrids, which is unlikely given the "maximum amount of hybrid issued per year" constraint implies we are looking at *issuance* or maintaining/increasing the buffer. Advising a target of 7.5% would imply maintaining the status quo or slight reduction. Advising 11.25% or 15% implies further issuance.

**2. Strategic Context and Cash Flow Needs**
*   **Suez Acquisition Integration:** The data shows a massive increase in Assets (from 53B to 73B) and Goodwill (from 6.2B to 11.6B) between 2022 and 2023. This reflects the completion of the Suez acquisition. The "Contribution Of Hybrid Debt Suez SA" of 1,623.9 million EUR indicates that Veolia inherited hybrid instruments from Suez.
*   **Deleveraging Pressure:** Post-acquisition, companies typically face pressure to deleverage to restore credit ratings. Veolia's Net Finance Costs increased significantly (from -342M to -632M), and Interest Paid rose from 357M to 637M.
*   **Cash Flow:** Operating Cash Flow is strong (4,148M EUR in 2022), but Investing Activities show a large net inflow (4,523M EUR), largely due to the "Proceeds From Sales Or Maturity Of Financial Instruments" (9,995M EUR) which likely relates to the recycling of Suez shares or divestitures required by regulators. This suggests Veolia is actively managing its balance sheet through asset sales rather than just debt issuance.
*   **Dividend Policy:** Dividends paid increased significantly (534M to 990M), indicating a commitment to shareholder returns which consumes free cash flow that could otherwise pay down debt.

**3. Assessment of Hybrid Utility**
*   **Rating Preservation:** Veolia is an Investment Grade issuer. The acquisition of Suez likely strained its leverage metrics. Hybrid bonds are equity-credited (typically 50-100% depending on terms, S&P often gives 50% or more for strong hybrids) and help lower reported leverage ratios (Debt/EBITDA or Debt/Capital).
*   **Current Level vs. Cap:** The current hybrid level is ~7.7%. The S&P cap is 15%.
*   **Market Conditions:** The swap curves and bond spreads in 2022 show a significant increase in yields (10Y Swap avg 1.926% in 2022 vs -0.143% in 2020). The cost of debt has risen. Issuing new hybrids is more expensive now than in previous years. However, hybrids are still cheaper than equity and can be deferred (coupons), providing flexibility.
*   **Guideline Matching:**
    *   **0% / 3.75%:** Incorrect. Veolia already exceeds this. Reducing hybrids would worsen leverage metrics, which is counter-intuitive post-acquisition.
    *   **7.5%:** This represents the current state. If Veolia were purely focused on organic growth with low capex, this might be sufficient. However, it is in a post-M&A integration phase with high debt levels.
    *   **11.25%:** This option aligns with "High capex intensity OR large acquisition pipeline" and "Significant leverage pressure." Veolia has just completed a transformational acquisition (Suez). It needs to optimize its capital structure to preserve its Investment Grade rating. The existing hybrid buffer (~7.7%) provides some relief, but increasing it towards 11.25% would provide additional headroom for deleveraging through equity credit without diluting shareholders. The guideline notes "Investment grade preservation strongly dependent on capital structure optimization."
    *   **15%:** This is for "Very high refinancing needs OR transformational capex/M&A program" with "Material downgrade risk without hybrid support." While the Suez deal was transformational, Veolia has generated strong operating cash flow and is divesting assets (evidenced by the investing cash flow). It does not appear to be in *distress* or facing an *immediate* material downgrade risk that *requires* maxing out the hybrid cap. Maxing out to 15% would significantly increase the cost of capital (hybrids are expensive) and might be viewed negatively by rating agencies if overused without clear necessity.

**Conclusion:**
Veolia is in a post-acquisition phase where leverage management is critical. It already utilizes hybrids at ~7.7%. To further support its leverage metrics and preserve its rating while managing the high cost of debt in the 2022/2023 environment, a moderate increase in the hybrid proportion is advisable. Moving from ~7.7% to **11.25%** allows for better leverage optimization ("meaningfully improves adjusted leverage metrics" / "IG preservation dependent on capital structure optimization") without over-leveraging the equity credit component to the maximum 15%, which is reserved for more distressed or extremely capital-intensive scenarios. The 11.25% level acknowledges the "significant leverage pressure" from the Suez integration while respecting the rising cost of capital.

<answer>11.25%</answer>