Dim i As Long, j As Long
Application.DisplayAlerts = False
For i = 1 To Range("C65536").End(xlUp).Row
j = 1
While Cells(i + j, 3) = Cells(i, 3)
Range(Cells(i, 1), Cells(i + j, 1)).MergeCells = True
Range(Cells(i, 2), Cells(i + j, 2)).MergeCells = True
Range(Cells(i, 3), Cells(i + j, 3)).MergeCells = True
Range(Cells(i, 4), Cells(i + j, 4)).MergeCells = True
Range(Cells(i, 5), Cells(i + j, 5)).MergeCells = True
Range(Cells(i, 6), Cells(i + j, 6)).MergeCells = True
Range(Cells(i, 7), Cells(i + j, 7)).MergeCells = True
Range(Cells(i, 8), Cells(i + j, 8)).MergeCells = True
j = j + 1
Wend
i = i + j - 1
Next
Application.DisplayAlerts = True