CERTIFICATIONS PURSUANT TO SECTION 906
EX-99.906CERT



                                  CERTIFICATION


R. Jay Gerken, Chief Executive Officer, and Richard L. Peteka, Chief Financial
Officer of Smith Barney Sector Series Inc. - Smith Barney Technology Fund (the
"Registrant"), each certify to the best of his or her knowledge that:

1. The Registrant's periodic report on Form N-CSR for the period ended October
31, 2003 (the "Form N-CSR") fully complies with the requirements of section
15(d) of the Securities Exchange Act of 1934, as amended; and

2. The information contained in the Form N-CSR fairly presents, in all material
respects, the financial condition and results of operations of the Registrant.


Chief Executive Officer                     Chief Financial Officer
Smith Barney Sector Series Inc.-            Smith Barney Sector Series Inc.-
Smith Barney Technology Fund                Smith Barney Technology Fund


/s/ R. Jay Gerken                           /s/ Richard L. Peteka
- -------------------------------             ---------------------------
R. Jay Gerken                               Richard L. Peteka
Date:  January 2, 2004                      Date:  January 2, 2004


This certification is being furnished to the Securities and Exchange Commission
solely pursuant to 18 U.S.C. ss. 1350 and is not being filed as part of the Form
N-CSR with the Commission.