With Worksheets("Viaduc de l'Arc")
Dim j as long, i as long, Unique as New Collection, Etp as range
set Unique = nothing
j = .Range("a3").End(xlDown).Row
'Boucle sur la colonne A, crée une liste sans doublon
For i = 3 To j
On Error Resume Next
Unique.Add .Cells(i, 1), CStr(.Cells(i, 1))
On Error GoTo 0
Next i
End With
'Affiche la liste d'entreprises
For Each Etp In Unique
Me.ListBox1.AddItem Etp
Next Etp