That is excellent guys. Both queries work as expected. I have modified the query a little bit to accomodate a case when col3 is negative. In that case it means that for company col1 is a loss but for comany col2 is a plus.so for examble for the following values;
col1 col2 col3
A    B    100
B    A    -50
A    C    200
A    D    100
A    B    150
B    F    200
The result of the modified queries:
SELECT CASE WHEN col1 <= col2 THEN col1 ELSE col2 END AS col1,
 CASE WHEN col1 <= col2 THEN col2 ELSE col1 END AS col2,
 SUM( CASE WHEN col3 < 0 THEN col3 * -1 ELSE col3 END ) AS col3
FROM SampleData
GROUP BY CASE WHEN col1 <= col2 THEN col1 ELSE col2 END,
 CASE WHEN col1 <= col2 THEN col2 ELSE col1 END;

SELECT d.col1, d.col2, col3 = SUM(IIF (d.col3 < 0, d.col3 * -1, d.col3))
 FROM (
   SELECT col1 = IIF(col1<=col2, col1, col2)
      ,col2 = IIF(col1<=col2, col2, col1)
      ,col3
    FROM SampleData
   ) d
GROUP BY d.col1, d.col2
;
Result:
A    B    300
A    C    200
A    D    100
B    F    200

That is what I wanted!!
I got all the help I requested. Thank you very much. From my prespective we can close this thread, Not sure who is going to do it.