To estimate the FFO / Net Debt ratio for 2022 based on S&P methodology, we need to calculate the Funds From Operations (FFO) and the Net Debt for the period ending 2022-01-01 (which represents the full year 2021 data) or the period ending 2023-01-01 (which represents the full year 2022 data). The prompt asks for the 2022 estimate, so we use the interval 2022-01-01 - 2023-01-01 for income statement and cash flow items, and the balance sheet date 2023-01-01 for debt, cash, and interest figures.

1. **Calculate FFO (Funds From Operations):**
According to S&P methodology, FFO is generally calculated as:
FFO = Profit/Loss Before Tax + Finance Costs + Depreciation & Amortisation - Share of Profit of Associates/JVs (since it's non-cash) - Income Tax Expense
Using the values for 2022-01-01 - 2023-01-01:
- Profit Loss Before Tax = -1,233,000,000 EUR
- Finance Costs = 300,000,000 EUR
- Depreciation And Amortisation Expense = 1,233,000,000 EUR
- Share Of Profit Loss Of Associates And Joint Ventures = 120,000,000 EUR
- Income Tax Expense Continuing Operations = -354,000,000 EUR (Note: This is a negative tax expense, indicating a tax income/benefit. In S&P adjustments, we subtract the tax *benefit* from operating cash flow or add back the actual tax paid from the cash flow statement. Let's use the cash taxes paid for a more precise S&P FFO calculation).

S&P FFO using cash taxes:
FFO = Profit/Loss Before Tax + Finance Costs + D&A - Share of JVs/Associates - Cash Taxes Paid
FFO = -1,233,000,000 + 300,000,000 + 1,233,000,000 - 120,000,000 - 231,000,000
FFO = -231,000,000 EUR.

Wait, let's recalculate the P&L add-backs:
P&L Before Tax = -1,233,000,000
Add: Finance Costs = +300,000,000
Add: D&A = +1,233,000,000
Less: Equity method result = -120,000,000
Subtotal = 180,000,000 EUR.
Now, subtracting the cash taxes paid of 231,000,000 EUR yields an FFO of -51,000,000 EUR.

Let's double-check with the standard S&P formula using reported tax expense (adjusted for non-cash items): 
Because the reported income tax is a benefit (-354,000,000), standard S&P accounting replaces this with actual cash taxes paid (231,000,000) to avoid adding non-cash tax benefits to FFO. 
Operating items (PBT + D&A + Interest - JVs) = -1,233m + 1,233m + 300m - 120m = 180m.
Subtracting cash taxes: 180m - 231m = -51m.

(If we incorrectly used reported tax benefit, it would be 180m - (-354m) = 534m, which vastly overstates cash generation. S&P strictly uses cash taxes or adjusts for non-cash tax benefits).

2. **Calculate Net Debt:**
Net Debt = Total Debt - Cash & Cash Equivalents.
Total Debt typically includes Long-term Borrowings, Short-term Borrowings, and Current Bank Overdrafts.
At 2023-01-01:
- Longterm Borrowings = 19,006,000,000 EUR
- Shortterm Borrowings = 709,000,000 EUR
- Current Bank Overdrafts = 0 EUR
Total Debt = 19,006,000,000 + 709,000,000 = 19,715,000,000 EUR.

Cash and Cash Equivalents at 2023-01-01 = 6,547,000,000 EUR.

Net Debt = 19,715,000,000 - 6,547,000,000 = 13,168,000,000 EUR.

3. **Calculate FFO / Net Debt:**
Ratio = FFO / Net Debt = -51,000,000 / 13,168,000,000 = -0.00387...

Expressed as a percentage, S&P ratios are often presented in percentage terms (e.g. -0.4%), or as a decimal ratio (-0.004). Following the standard notation for such ratios without specifying format, a decimal representation is safest: -0.00387. Rounded to four decimal places, it is -0.0039. 

Let's review the formula one more time. S&P defines FFO as Net Income + D&A + Interest Expense - Equity Earnings + Income Taxes (cash). 
Net Income = -879,000,000
D&A = 1,233,000,000
Interest Expense = 300,000,000
Equity Earnings = 120,000,000
Subtotal = -879m + 1,233m + 300m - 120m = 534m.
Cash Taxes = 231,000,000.
FFO = 534m - (231m + 879m? No, cash tax is just 231m). Wait. Net Income includes the -354m tax benefit. So to substitute the -354m tax benefit with the 231m cash tax, we must add back the 354m benefit (making pre-tax income 180m) and subtract the 231m cash paid, leading back to 180m - 231m = -51m. The math is completely consistent.

FFO = -51,000,000
Net Debt = 13,168,000,000
Ratio = -0.003873...

<answer>-0.0039</answer>