The company currently carries a relatively modest amount of hybrid capital (≈ 2.1 bn EUR), representing only about 7 % of total capital and 27 % of equity. Its credit profile is solid thanks to a regulated transmission business and strong operating cash flows, but it is also highly leveraged (≈ 21 bn EUR of debt) and currently loss‑making. Hybrid bonds provide useful equity‑like flexibility, yet their cost (≈ 2.7 % yield) is higher than senior‑debt funding in the current market (swap rates ≈ 1.7‑1.9 % and IG corporate yields ≈ 1‑1.3 %). A modest increase in the hybrid‑bond share to about one‑quarter of total capital would improve the equity cushion, help maintain rating headroom, and still keep financing costs manageable. Anything higher (50 %‑100 %) would raise the overall cost of capital materially without additional benefit, while a zero‑percent target would forgo the flexibility already embedded in the existing hybrid structure.

**Recommended hybrid‑bond proportion:** 25 % of total capital.

<answer>25%</answer>