Error at line 6 ORA-00933: SQL command not properly ended ORA-06512: at line 16

not seeing anything obvious

Error at line 6
ORA-00933: SQL command not properly ended
ORA-06512: at line 16
DECLARE
 CURSOR PartTables IS
    SELECT TABLE_NAME, PARTITION_NAME, HIGH_VALUE
    FROM DBA_TAB_PARTITIONS
    where TABLE_owner in ('FDW','FDWSTG','FDW3NF')
    ORDER BY TABLE_NAME, PARTITION_POSITION;

    cur SYS_REFCURSOR;
    r INTEGER;
    highValue VARCHAR2(100);

BEGIN
   FOR aTab IN PartTables LOOP
      EXECUTE IMMEDIATE 'BEGIN :ret := '||aTab.HIGH_VALUE||'; END;' USING OUT highValue;
      IF highValue NOT IN ('DEFAULT', 'MAXVALUE') THEN
         OPEN cur