bonsoir,
Voici une solution :
Sub Galopin()
Dim i&, Arr, rng As Range
Application.ScreenUpdating = False
Set rng = Range("A1").CurrentRegion
With rng
Arr = .Offset(1).Resize(.Rows.Count - 1).Value
End With
For i = UBound(Arr) - 2 To 1 Step -3
Arr(i, 3) = Arr(i + 1, 2)
Arr(i, 4) = Arr(i + 2, 2)
Next
rng.Offset(1).Resize(rng.Rows.Count - 1) = Arr
For i = UBound(Arr) + 1 To 4 Step -3
Rows(i).Delete
Rows(i - 1).Delete
Next
End Sub
A+