S&P’s FFO / Net debt is generally estimated as:

\[
\text{FFO / Net debt} = \frac{\text{Funds from operations}}{\text{Adjusted net debt}}
\]

Using the available VINCI 2022 data, a practical approximation is:

**1. Estimate FFO**

Start from cash flow from operations before working capital, then adjust for items typically excluded from FFO such as working capital movements and include recurring operating cash generation after interest and tax.

Given:
- Cash flows from operations before changes in working capital = €10,215m
- Income taxes paid = €1,603m
- Interest paid and received classified as operating activities = €563m

Approximate FFO:

\[
10{,}215 - 1{,}603 - 563 = 8{,}049
\]

So estimated FFO ≈ **€8.049bn**.

This is also consistent with starting from reported operating cash flow of €9.387bn and excluding the working capital movement benefit/drag and other operating cash-flow classifications.

**2. Estimate net debt**

Use financial debt components less cash and cash-management financial assets.

Debt components at 2022 year-end / 2023-01-01:
- Noncurrent bonds issued = €20,425m
- Other noncurrent borrowings = €3,205m
- Noncurrent lease liabilities = €1,580m
- Current lease liabilities = €522m
- Short-term borrowings = €6,368m

Gross debt:

\[
20{,}425 + 3{,}205 + 1{,}580 + 522 + 6{,}368 = 32{,}100
\]

Cash and liquid financial assets:
- Cash and cash equivalents = €12,578m
- Current cash management financial assets = €755m

Net debt:

\[
32{,}100 - 12{,}578 - 755 = 18{,}767
\]

So estimated net debt ≈ **€18.767bn**.

**3. Calculate FFO / Net debt**

\[
\frac{8{,}049}{18{,}767} = 0.4289
\]

So the estimated FFO / Net debt ratio for 2022 is approximately **42.9%**.

<answer>42.9%</answer>