SELECT
max(LTRIM(SYS_CONNECT_BY_PATH(VC2AREACODE, ';'), ';')) B
FROM (
SELECT t0.VC2AREACODE, rownum RN FROM
(SELECT DISTINCT VC2AREACODE FROM CT_CUSELLRATEDETAIL_PREFIX WHERE NUMCUSELLRATEDMSGUID='997416' ORDER BY VC2AREACODE) t0
)
START WITH RN = 1
CONNECT BY RN - 1 = PRIOR RN