Hi, Try this:-
Sub MG04Jun34
Dim Rng As Range, Rng2 As Range, Dn As Range, n As Long
Set Rng = Range(Range("A2"), Range("A" & Rows.Count).End(xlUp))
Set Rng2 = Range(Range("B2"), Range("B" & Rows.Count).End(xlUp))
Set Rng = Union(Rng, Rng2)
ReDim ray(1 To Rng.Count)
    With CreateObject("scripting.dictionary")
        .CompareMode = vbTextCompare
        For Each Dn In Rng
            If Not .Exists(Dn.Value) Then
                n = n + 1
                .Add Dn.Value, n
                If Dn.Column = 1 Then ray(n) = Dn.Value
            Else
                If Dn.Column = 2 Then
                      ray(.Item(Dn.Value)) = ""
                End If
            End If
        Next
End With
With Range("C2").Resize(n)
    .Value = Application.Transpose(ray)
    .SpecialCells(xlCellTypeBlanks).Delete
 End With
End Sub
Regards Mick