CERTIFICATIONS PURSUANT TO SECTION 906 EX-99.906CERT CERTIFICATION R. Jay Gerken, Chief Executive Officer, and Richard L. Peteka, Chief Financial Officer of The Travelers Series Trust - Convertible Securities Portfolio (the "Registrant"), each certify to the best of his knowledge that: 1. The Registrant's periodic report on Form N-CSR for the period ended December 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 The Travelers Series Trust - The Travelers Series Trust - Convertible Securities Portfolio Convertible Securities Portfolio /s/ R. Jay Gerken /s/ Richard L. Peteka - ----------------------------- --------------------------- R. Jay Gerken Richard L. Peteka Date: March 10, 2004 Date: March 10, 2004 This certification is being furnished to the Securities and Exchange Commission solely pursuant to 18 U.S.C. Section 1350 and is not being filed as part of the Form N-CSR with the Commission. CERTIFICATIONS PURSUANT TO SECTION 906 EX-99.906CERT CERTIFICATION R. Jay Gerken, Chief Executive Officer, and Richard L. Peteka, Chief Financial Officer of The Travelers Series Trust - Mid Cap Growth Portfolio (the "Registrant"), each certify to the best of his knowledge that: 1. The Registrant's periodic report on Form N-CSR for the period ended December 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 The Travelers Series Trust - The Travelers Series Trust - Mid Cap Growth Portfolio Mid Cap Growth Portfolio /s/ R. Jay Gerken /s/ Richard L. Peteka - ----------------------------- --------------------------- R. Jay Gerken Richard L. Peteka Date: March 10, 2004 Date: March 10, 2004 This certification is being furnished to the Securities and Exchange Commission solely pursuant to 18 U.S.C. Section 1350 and is not being filed as part of the Form N-CSR with the Commission. CERTIFICATIONS PURSUANT TO SECTION 906 EX-99.906CERT CERTIFICATION R. Jay Gerken, Chief Executive Officer, and Richard L. Peteka, Chief Financial Officer of The Travelers Series Trust - Merrill Lynch Large Cap Core Portfolio (the "Registrant"), each certify to the best of his knowledge that: 1. The Registrant's periodic report on Form N-CSR for the period ended December 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 The Travelers Series Trust - The Travelers Series Trust - Merrill Lynch Large Cap Core Merrill Lynch Large Cap Core Portfolio Portfolio /s/ R. Jay Gerken /s/ Richard L. Peteka - ----------------------------- --------------------------- R. Jay Gerken Richard L. Peteka Date: March 10, 2004 Date: March 10, 2004 This certification is being furnished to the Securities and Exchange Commission solely pursuant to 18 U.S.C. Section 1350 and is not being filed as part of the Form N-CSR with the Commission.