SCHEDULE 14A INFORMATION

                    Proxy Statement Pursuant to Section 14(a)
                     of the Securities Exchange Act of 1934
                               (Amendment No.)

Filed by the Registrant                               [X]
Filed by a Party other than the Registrant            [ ]

Check the appropriate box:

[ ]   Preliminary Proxy Statement
[ ]   Definitive Proxy Statement
[X]   Definitive Additional Materials
[ ]   Soliciting Material Pursuant to Section.240-14a-11(c) or Section.240-
      14a-12
[ ]   Confidential, for Use of the Commission Only (as permitted by Rule
      14a-6(e)(2))

                        Franklin Principal Maturity Trust
                (Name of Registrant as Specified In Its Charter)

                        Franklin Principal Maturity Trust
                   (Name of Person(s) Filing Proxy Statement)

Payment of Filing Fee (Check the appropriate box):

[X] No fee required

[ ] Fee computed on table below per Exchange Act Rules 14a-6(i)(1) and 0-11

     (1)   Title of each class of securities to which transaction applies:

     (2)   Aggregate number of securities to which transaction applies:

     (3)   Per unit price or other underlying value of transaction computed
           pursuant to Exchange Act Rule 0-11 (set forth the amount on which
           the filing fee is calculated and state how it was determined):

     (4)   Proposed maximum aggregate value of transaction:

     (5)   Total fee paid:

[ ]   Fee paid previously with preliminary material.

[ ]   Check box if any part of the fee is offset as provided by Exchange Act
      Rule 0-11(a)(2) and identify the filing for which the offsetting fee
      was paid previously. Identify the previous filing by registration
      statement number, or the Form or Schedule and the date of its filing.

      1)   Amount Previously Paid:

      2)   Form, Schedule or Registration Statement No.:

      3)   Filing Party:

      4)   Date Filed:

                        FRANKLIN PRINCIPAL MATURITY TRUST
                            777 Mariners Island Blvd.
                                  P.O. Box 7777
                            San Mateo, CA 94403-7777

                  REMINDER: SPECIAL MEETING OF SHAREHOLDERS
                             TO BE HELD JUNE 5, 1998

Dear Shareholder:

We have  not  yet  received  your  vote  for the  upcoming  Special  Meeting  of
Shareholders  scheduled  to be held June 5, 1998.  It is critical  that you vote
your  proxy.  All votes are vital no matter  how many  shares  you hold and YOUR
SHARES CANNOT BE REPRESENTED UNLESS WE RECEIVE VOTING INSTRUCTIONS FROM YOU! The
Reorganization  proposal  requires the  affirmative  vote of  two-thirds  of the
outstanding  shares  of the  Fund,  making  it  critical  that all  shareholders
participate!  Thus far, we have received voting  instructions from approximately
50% of the outstanding  shares of which an overwhelming  90% are voting in favor
of the  Reorganization.  In  order  for your  shares  to be  represented  at the
meeting, we must receive your vote on or before Friday, JUNE 5, 1998.

The meeting has been  called in order to consider  and approve a  Reorganization
which would result in an exchange of the assets of Franklin  Principal  Maturity
Trust for Class I shares of  Franklin  Income  Fund.  Franklin  Income Fund is a
series of Franklin  Custodian Funds,  Inc., an open-end  investment company also
managed by Franklin Advisers,  Inc. If the proposal is approved,  on the date of
the  Reorganization,  you will receive Class I shares of the Income Series equal
to the value of your  investment  in the Fund on that  date (at net asset  value
rather than the New York Stock Exchange  price).  Please see the proxy statement
which was previously mailed to you for further information.

For  your  convenience,  we have  established  three  easy  methods  by which to
register your vote:

      1. BY PHONE:    Please call SHAREHOLDER COMMUNICATIONS CORPORATION toll
                      free at 1-800-733-8481, EXTENSION "480." Operators will be
                      available to take your vote Monday thru Friday between the
                      hours of 9:00 a.m. and 11:00 p.m. and Saturday from 12:00
                      p.m. to 6:00 p.m. Eastern Time.

      2. BY FAX:      Fax your executed proxy to us toll free at 1-800-733-1885,
                      anytime.

      3. BY MAIL:     Return your executed proxy in the enclosed postage paid 
                      envelope. Please utilize this option only if methods 1 and
                      2 are both unavailable, as we may not receive your proxy 
                      by mail by the June 5, 1998 meeting.

If you have any  questions  regarding  the proxy  statement  or need  assistance
executing your vote, please call SHAREHOLDER  COMMUNICATIONS  CORPORATION at the
above-mentioned number.

We urge you to act promptly so that your vote may be received before the meeting
and further proxy solicitation expenses will not be incurred.

Thank you for your consideration of this matter.


PROXY

FRANKLIN PRINCIPAL MATURITY TRUST

SPECIAL MEETING OF SHAREHOLDERS JUNE 5, 1998


   The  undersigned  hereby  revokes  all  previous  proxies  for his shares and
appoints  Rupert H.  Johnson,  Harmon E.  Burns,  Deborah R. Gatzek and Larry L.
Greene,  and  each of  them,  proxies  of the  undersigned  with  full  power of
substitution  to vote all  shares of  Franklin  Principal  Maturity  Trust  (the
"Fund") which the  undersigned is entitled to vote at the Fund's Special Meeting
to be held at 777 Mariners  Island  Blvd.,  San Mateo,  California  at 2:00 p.m.
Pacific time, on the 5th day of June, 1998,  including any adjournment  thereof,
upon such business as may be brought before the Special Meeting.

   THIS PROXY IS SOLICITED ON BEHALF OF THE BOARD OF TRUSTEES.  IT WILL BE VOTED
AS SPECIFIED. IF NO SPECIFICATION IS MADE, THIS PROXY SHALL BE VOTED IN FAVOR OF
THE PROPOSAL  REGARDING THE REORGANIZATION OF THE FUND PURSUANT TO THE AGREEMENT
AND PLAN OF  REORGANIZATION  WITH FRANKLIN  CUSTODIAN  FUNDS,  INC.  ("CUSTODIAN
FUNDS") AND WITHIN THE  DISCRETION OF THE  PROXYHOLDERS  AS TO ANY OTHER MATTERS
THAT MAY LEGALLY COME BFORE THE MEETING.

SEE REVERSE SIDE                                      SEE REVERSE SIDE

CONTINUED AND TO BE SIGNED ON REVERSE SIDE

X Please mark votes as in this example.
                                                     FOR  AGAINST    ABSTAIN

1  To approve an Agreement and Plan of
   Reorganization between the Fund and Custodian
   Funds on behalf of the Income Series that
   provides for the acquisition of substantially
   all of the assets of the Fund in exchange for
   Class I shares of the Income Series, the
   distribution of such shares to the
   shareholders of the Fund, and the dissolution
   of the Fund.

                                                      GRANT     WITHHOLD

2  To grant the proxy holders the authority to
   vote in their discretion upon any other
   business that may legally come before the
   meeting.
- ------------------------------------------------------------------------------

                                    MARK HERE FOR ADDRESS CHANGE AND NOTE AT
                                    LEFT

                                    PLEASE SIGN AND PROMPTLY RETURN IN THE
                                    ACCOMPANYING ENVELOPE.  NO POSTAGE
                                    REQUIRED IF MAILED IN THE U.S.

                                    NOTE:  PLEASE SIGN EXACTLY AS YOUR NAME
                                    APPEARS ON THE PROXY.  IF SIGNING FOR
                                    ESTATES, TRUSTS OR CORPORATIONS, TITLE OR
                                    CAPACITY SHOULD BE STATED.  IF SHARES ARE
                                    HELD JOINTLY, EACH HOLDER MUST SIGN.


Signature: _____________ Date:______ Signature: _______________ Date: ________