<Page>

     CERTIFICATION PURSUANT TO SECTION 906 OF THE SARBANES OXLEY ACT OF 2002


This certification is provided pursuant to Section 906 of the Sarbanes-Oxley Act
of 2002, 18 U.S.C. Section 1350, and accompanies the report on Form N-CSR for
the period ended June 30, 2003 of the JPMorgan Multi-Manager Small Cap Growth
Fund and JPMorgan Multi-Manager Small Cap Value Fund, each a series of J.P.
Morgan Fleming Series Trust (the "Registrant").

I, George C.W. Gatch, certify that:

1.   The Form N-CSR fully complies with the requirements of Section 13(a) or
     15(d) of the Securities Exchange Act of 1934 (15 U.S.C. 78m(a) or 78o(d));
     and

2.   The information contained in the Form N-CSR fairly presents, in all
     material respects, the financial condition and results of operations of
     JPMorgan Multi-Manager Small Cap Growth Fund and JPMorgan Multi-Manager
     Small Cap Value Fund, each a series of the Registrant.


/s/ George C.W. Gatch
- -----------------------------
George C.W. Gatch
President


August 25, 2003
- -----------------------------
Date

A signed original of this written statement required by Section 906 has been
provided to the Registrant and will be retained by the Registrant and furnished
to the Securities and Exchange Commission or its staff upon request.

<Page>

     CERTIFICATION PURSUANT TO SECTION 906 OF THE SARBANES OXLEY ACT OF 2002

This certification is provided pursuant to Section 906 of the Sarbanes-Oxley Act
of 2002, 18 U.S.C. Section 1350, and accompanies the report on Form N-CSR for
the period ended June 30, 2003 of the JPMorgan Multi-Manager Small Cap Growth
Fund and JPMorgan Multi-Manager Small Cap Value Fund, each a series of J.P.
Morgan Fleming Series Trust (the "Registrant").

I, David Wezdenko, certify that:

1.   The Form N-CSR fully complies with the requirements of Section 13(a) or
     15(d) of the Securities Exchange Act of 1934 (15 U.S.C. 78m(a) or 78o(d));
     and

2.   The information contained in the Form N-CSR fairly presents, in all
     material respects, the financial condition and results of operations of
     JPMorgan Multi-Manager Small Cap Growth Fund and JPMorgan Multi-Manager
     Small Cap Value Fund, each a series of the Registrant.


/s/ David Wezdenko
- -----------------------------
David Wezdenko
Treasurer


August 25, 2003
- -----------------------------
Date

A signed original of this written statement required by Section 906 has been
provided to the Registrant and will be retained by the Registrant and furnished
to the Securities and Exchange Commission or its staff upon request.