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                                                                    Exhibit 4.23



         THIS TRUST PREFERRED SECURITY IS A GLOBAL CERTIFICATE WITHIN THE
MEANING OF TRUST AGREEMENT HEREINAFTER REFERRED TO AND IS REGISTERED IN THE NAME
OF THE DEPOSITORY TRUST COMPANY (THE "DEPOSITORY") OR A NOMINEE OF THE
DEPOSITORY. THIS TRUST PREFERRED SECURITY IS EXCHANGEABLE FOR TRUST PREFERRED
SECURITIES REGISTERED IN THE NAME OF A PERSON OTHER THAN THE DEPOSITORY OR ITS
NOMINEE ONLY IN THE LIMITED CIRCUMSTANCES DESCRIBED IN THE TRUST AGREEMENT AND
NO TRANSFER OF THIS TRUST PREFERRED SECURITY (OTHER THAN A TRANSFER OF THIS
TRUST PREFERRED SECURITY AS A WHOLE BY THE DEPOSITORY TO A NOMINEE OF THE
DEPOSITORY OR BY A NOMINEE OF THE DEPOSITORY TO THE DEPOSITORY OR ANOTHER
NOMINEE OF THE DEPOSITORY) MAY BE REGISTERED EXCEPT IN LIMITED CIRCUMSTANCES.

         UNLESS THIS TRUST PREFERRED SECURITY IS PRESENTED BY AN AUTHORIZED
REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY (55 WATER STREET, NEW YORK) TO
TECO CAPITAL TRUST I OR ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR
PAYMENT, AND ANY TRUST PREFERRED SECURITY ISSUED IS REGISTERED IN THE NAME OF
CEDE & CO. OR SUCH OTHER NAME AS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF
THE DEPOSITORY TRUST COMPANY AND ANY PAYMENT HEREON IS MADE TO CEDE & CO., ANY
TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY A PERSON IS
WRONGFUL INASMUCH AS THE REGISTERED OWNER HEREOF, CEDE & CO., HAS AN INTEREST
HEREIN.

Certificate Number: 1                       Number Of Trust Preferred Securities
                                            CUSIP No. 87875R208

                Certificate Evidencing Trust Preferred Securities

                                       of

                              TECO CAPITAL TRUST I

                        8.50% TRUST PREFERRED SECURITIES
              (Liquidation Amount $25 Per Trust Preferred Security)

         TECO Capital Trust I, a statutory business trust created under the laws
of the State of Delaware (the "Trust"), hereby certifies that Cede & Co. (the
"Holder") is the registered owner of 8,000,000 Trust Preferred Securities of the
Trust representing an undivided beneficial ownership interest in the assets of
the Trust and designated the 8.50% Trust Preferred Securities (the "Trust
Preferred Securities"). The Trust Preferred Securities are transferable on the
books and records of the Trust, in person or by a duly authorized attorney, upon
surrender of this certificate duly endorsed and in proper form for transfer as
provided in Section 5.4 of the Trust Agreement (as defined below). The
designations, rights, privileges, restrictions, preferences and other terms and
provisions of the Trust Preferred Securities are set forth in, and this
certificate and the Trust Preferred Securities represented hereby are issued and
shall in all respects be subject to the terms and provisions of, the Amended and
Restated Trust Agreement of the Trust
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dated as of December 1, 2000 as the same may be amended from time to time (the
"Trust Agreement") including the designation of the terms of Trust Preferred
Securities as set forth therein. The Trust will furnish a copy of the Trust
Agreement to the Holder without charge upon written request to the Trust at its
principal place of business or registered office.

         In Witness Whereof, the Property Trustee of the Trust has executed this
certificate this 20th day of December, 2000.

                                           TECO CAPITAL TRUST I

                                           By:   THE BANK OF NEW YORK
                                                 As Property Trustee


                                           By: /s/ Philip A. Martone
                                              ---------------------------------
                                               Name:   Philip A. Martone
                                               Title:  Vice President