To determine the S&P estimated FFO (Funds From Operations) to Net Debt ratio for Bouygues at the end of 2022, we must apply standard S&P Global Ratings adjustments to the company's reported figures.

1. **Calculate FFO:**
Under S&P methodology, FFO is generally equivalent to the operating cash flow before changes in working capital. In standard French financial reporting (which Bouygues uses), this exact metric is reported as the "Capacité d'autofinancement" (CAF), which translates to "Cash Flow After Cost Of Net Debt, Interest Expense On Lease Obligations And Income Taxes Paid". 
From the data provided:
* FFO = 3,324,000,000 EUR

2. **Calculate S&P Adjusted Net Debt:**
Bouygues' reported "Net Debt" standardly excludes lease liabilities. However, S&P Global Ratings capitalizes operating leases and includes them in their Adjusted Net Debt metric. 
From the data provided:
* Reported Net Debt (2023-01-01) = 7,440,000,000 EUR
* Noncurrent Lease Liabilities = 2,107,000,000 EUR
* Current Lease Liabilities = 498,000,000 EUR

S&P Adjusted Net Debt = Reported Net Debt + Total Lease Liabilities 
= 7,440,000,000 + 2,107,000,000 + 498,000,000 
= 10,045,000,000 EUR
*(Note: S&P may also add post-retirement/pension obligations to this figure. Since the explicit breakout for underfunded pensions is not provided strictly in the stated facts, we proceed with the standard lease-adjusted debt).*

3. **Calculate the Ratio:**
FFO / Net Debt = 3,324,000,000 / 10,045,000,000 
= 0.3309 (or 33.1%)

<answer>0.33</answer>