To assess the suitability of Bouygues SA for the issuance of hybrid bonds, we evaluate its business profile, financial standing, and the strategic rationale for such an instrument based on the provided data.

**Business and Financial Profile:**
Bouygues is a diversified industrial group with significant operations in construction, energy services (Equans), and telecommunications. While parts of its business (like telecommunications infrastructure) share some characteristics with stable utilities, the overall group is inherently exposed to the cyclicality of the construction and services sectors. The 2022 data shows a significant increase in both goodwill (from 7.4 billion EUR to 12.6 billion EUR) and long-term borrowings (from 5.8 billion EUR to 11.6 billion EUR), largely driven by M&A activity, such as the acquisition of Equans. 

**Financial Ratios and Trends:**
The S&P Net Debt/EBITDA ratio of 3.26 indicates a leverage profile that is approaching the upper end of the BBB range. Crucially, Moody’s reports a "deteriorating" leverage trend, which suggests that the company’s credit metrics are under pressure following its recent expansionary phase. 

**Hybrid Bond Considerations:**
1. **Rationale:** A hybrid bond could provide the necessary equity-like capital to stabilize credit metrics, improve the FFO/debt ratio (currently 0.2446), and provide rating headroom following the recent debt-funded acquisition.
2. **Precedent:** Bouygues has never issued hybrid bonds. Per the provided guidelines, the absence of prior hybrid issuance is a strong signal that the instrument is not currently a core part of the firm's capital structure strategy, suggesting a lower likelihood of it being deemed "Strongly Suitable."
3. **Sectoral Context:** While Bouygues has infrastructure-like components, it is primarily a large-cap industrial group rather than a regulated utility or pure-play infrastructure firm. The suitability for hybrids is therefore more "opportunistic" than "structural."

**Conclusion:**
Given the deteriorating trend in leverage and the need for credit support following the large Equans acquisition, a hybrid issuance would be a rational tool to shore up the balance sheet and protect the company's credit rating. However, because it is not a traditional issuer of such debt and the company retains a solid investment-grade footprint, the issuance would be strategic and opportunistic rather than a core recurring requirement. This places it in the category of "Marginally Suitable."

<answer>Marginally Suitable</answer>