The company’s current hybrid‑bond (deeply subordinated securities) balance is about €3.5 bn, which represents roughly 12 % of total financial debt and around 9 % of total capital. This level already provides a meaningful equity‑like buffer (rating agencies treat indefinite hybrids as quasi‑equity) while keeping leverage within a reasonable range (net‑debt/EBITDA ≈ 3–4× and interest coverage ≈ 8–9×). Raising the proportion to 25 % of capital would modestly increase the equity buffer, improve leverage metrics and maintain financial flexibility, especially given the company’s stable cash‑flow profile and the strategic need for acquisitions. A higher share (50 % or more) would elevate default risk and refinancing pressure, and the current rising‑rate environment makes overly heavy reliance on higher‑cost hybrid financing inadvisable. Hence, a 25 % reliance strikes an appropriate balance.

<answer>25%</answer>