0000950123-01-001517 SC 14D9/A 1 20010215 ACNIELSEN CORP 0001019878 8700 061454128 DE 1231 SC 14D9/A 34 005-47591 1547893 177 BROAD STREET STAMFORD CT 06901 2038344200 177 BROAD ST STAMFORD CT 06901 ACNIELSEN CORP 0001019878 8700 061454128 DE 1231 SC 14D9/A 177 BROAD STREET STAMFORD CT 06901 2038344200 177 BROAD ST STAMFORD CT 06901 SC 14D9/A 1 y45113a6sc14d9a.txt AMENDMENT NO. 6 TO SCHEUDLE 14D-9