To determine S&P's credit trend for ITALGAS S.P.A. from 2021 to 2022, we estimate the Adjusted EBITDA, FFO, and Adjusted Debt for both years according to standard S&P methodologies for regulated utilities.

**Step 1. Identify the Relevant Industry**
ITALGAS S.P.A. is an Italian natural gas distribution company. It operates under a regulatory framework, so it falls into the "Regulated Utilities" industry. For financial metrics, we apply S&P's general and utility-specific guidelines (e.g., standard EBITDA and net debt adjustments, including employee benefit liabilities). 

**Step 2 & 3. Calculate 2021 Adjusted EBITDA and FFO**
* **Adjusted EBITDA**: 
  Operating income (Profit/Loss from Operating Activities) = €583.2M
  (+) D&A and impairment losses = €445.3M
  Adjusted EBITDA = €583.2M + €445.3M = **€1,028.5M**

* **FFO (Funds From Operations)**:
  Adjusted EBITDA = €1,028.5M
  (-) Cash interest paid = €59.8M
  (-) Cash taxes paid = €206.9M
  FFO = €1,028.5M - €59.8M - €206.9M = **€761.8M**

**Step 4. Calculate 2021 Adjusted Debt**
* **Gross Debt**:
  Short-term financial liabilities = €591.2M
  Long-term financial liabilities = €5,785.7M
  Other current & non-current financial liabilities = €0.3M + €6.3M = €6.6M
  Pension deficit (Noncurrent provisions for employee benefits) = €95.6M
  Total Gross Debt = €6,479.1M
* **Cash & Equivalents** = €1,391.8M
* **Adjusted Debt** = €6,479.1M - €1,391.8M = **€5,087.3M**

**Step 5 & 6. 2021 Credit Metrics**
* **Adjusted Debt / Adjusted EBITDA** = €5,087.3M / €1,028.5M = **4.95x**
* **FFO / Adjusted Debt** = €761.8M / €5,087.3M = **14.97%**

**Step 7 & 8. Calculate 2022 Adjusted EBITDA and FFO**
* **Adjusted EBITDA**:
  Operating income = €641.3M
  (+) D&A and impairment losses = €479.2M
  Adjusted EBITDA = €641.3M + €479.2M = **€1,120.5M**

* **FFO**:
  Adjusted EBITDA = €1,120.5M
  (-) Cash interest paid = €53.7M
  (-) Cash taxes paid = €152.4M
  FFO = €1,120.5M - €53.7M - €152.4M = **€914.4M**

**Step 9. Calculate 2022 Adjusted Debt**
* **Gross Debt**:
  Short-term financial liabilities = €142.4M
  Long-term financial liabilities = €6,402.9M
  Other current & non-current financial liabilities = €0.3M + €0.03M = €0.33M
  Pension deficit = €69.9M
  Total Gross Debt = €6,615.5M
* **Cash & Equivalents** = €451.9M
* **Adjusted Debt** = €6,615.5M - €451.9M = **€6,163.6M**

**Step 10 & 11. 2022 Credit Metrics**
* **Adjusted Debt / Adjusted EBITDA** = €6,163.6M / €1,120.5M = **5.50x**
* **FFO / Adjusted Debt** = €914.4M / €6,163.6M = **14.84%**

**Step 12. Evaluate the Credit Trend**
* **Signal 1: Leverage (Adjusted Debt / Adjusted EBITDA)**  
  Change = 5.50x - 4.95x = +0.55x. Since the change is ≥ +0.2x, this metric points to a **Deteriorating** trend. The material reduction in the company's cash reserves (from roughly €1.39B to €452M) primarily drove this notable inflation in net debt. 
* **Signal 2: Cash-Flow Coverage (FFO / Adjusted Debt)**  
  Change = 14.84% - 14.97% = -0.0013 (-0.13 percentage points). Since the change sits strictly within the neutral band (-0.03 to +0.03), this reflects a **Stable** trajectory.

* **Conclusion**: With leverage increasing markedly by over half a turn—an unambiguous signal of deteriorating credit fundamentals based on debt-to-EBITDA—paired with a flat FFO-to-Debt reading, the overall directional momentum rules in favor of a negative assessment.

<answer>Deteriorating</answer>