Option Explicit
Sub Merging()
Dim i As Long
With Feuil1
'Fusion en ligne
For i = .Cells(3, .Columns.Count).End(xlToLeft).Column To 2 Step -1
If UCase(.Cells(3, i)) = UCase(.Cells(3, i - 1)) Then
.Cells(3, i - 1) = ""
.Range(Cells(3, i), Cells(3, i - 1)).Merge
.Range(Cells(3, i), Cells(3, i - 1)).HorizontalAlignment = xlCenter
End If
Next i
End With
End Sub