I would like to concatenate cells from a column based on the match in the
preceding column with a defined value.

Example:
Col. A B
Row1: T1 Jim
Row2: T3 Paul
Row3: T1 Joe
Row4: T2 Mike
Row5: T3 Caroline

The formula should return for T1 for instance: Jim;Joe;
(for T2: Mike;
for T3: Paul;Caroline;)
Cells in column A can repeat any number of times.

Thanks in advance,
Erny