Exhibit 1.A(8)(b)(xxiii)

                  SEVENTH AMENDMENT TO PARTICIPATION AGREEMENT

        THIS AGREEMENT is made by and among Security Life of Denver Insurance
Company, a life insurance company organized under the laws of the State of
Colorado (the "Company"), Variable Insurance Products Fund, an unincorporated
business trust organized under the laws of the Commonwealth of Massachusetts
(the "Fund"), and Fidelity Distributors Corporation, a Massachusetts corporation
(the "Underwriter") (collectively, the "Parties").

        WHEREAS, the Parties executed a participation agreement dated August 10,
1994 (the "Participation Agreement"), governing how shares of the Fund's
portfolios are to be made available to certain variable life insurance and/or
variable annuity contracts (the "Contracts") offered by the Company through
certain separate accounts (the "Separate Accounts");

        WHEREAS, the various contracts for which shares are purchased are listed
in Schedule A of the Participation Agreement;

        WHEREAS, the Parties have agreed that it is in their interests to add an
additional Contract and class of Fund to be purchased by the Separate Accounts;

        NOW, THEREFORE, in consideration of their mutual promises, the Company,
the Fund and the Underwriter agree as follows:

        1.     The Participation Agreement is hereby amended by substituting for
               the current Schedule A an amended Schedule A in the form attached
               hereto which adds the Strategic Benefit and Estate Designer
               Variable Universal Life policies to the list of Contracts funded
               by the Separate Accounts.

        2.     Section 2.5 of Article II. Representations and Warranties is
               hereby deleted and replaced in its entirety with the following:

               2.5.   (a) With respect to Initial Class shares, the Fund
                      currently does not intend to make any payments to finance
                      distribution expenses pursuant to Rule 12b-1 under the
                      1940 Act or otherwise, although it may make such payments
                      in the future. The Fund has adopted a "no fee" or
                      "defensive" Rule 12b-1 Plan under which it makes no
                      payments for distribution expenses. To the extent that it
                      decides to finance distribution expenses pursuant to Rule
                      12b-1, the Fund undertakes to have a board of trustees, a
                      majority of whom are not interested persons of the Fund,
                      formulate and approve any plan under Rule 12b-1 to finance
                      distribution expenses.


                      (b) With respect to Service Class shares and Service Class
                      2 shares, the Fund has adopted Rule 12b-1 Plans under
                      which it makes payments to finance distribution expenses.
                      The Fund represents and warrants that it has a board of
                      trustees, a majority of whom are not interested persons of
                      the Fund, which has formulated and approved each of its
                      Rule 12b-1 Plans to finance distribution expenses of the
                      Fund and that any changes to the Fund's Rule 12b-1 Plans
                      will be approved by a similarly constituted board of
                      trustees.


         3.    Paragraph 5.1 of Article V. Fees and Expenses is hereby amended
               to delete the following sentence as of the date of this
               Amendment, "Currently, no such payments are contemplated."








         4.    The Participation Agreement is hereby amended by substituting for
               the current Schedule C an amended Schedule C in the form attached
               hereto which adds certain other investment options to the
               Contracts funded by the Separate Accounts.

         5.    The Participation Agreement is hereby amended by substituting for
               the current Schedule D an amended Schedule D in the form attached
               hereto which adds certain classes of certain Fidelity Funds to
               some Contracts funded by the Separate Accounts.

Executed this 26th day of April, 2000.

Security Life of Denver                    Variable Insurance Products Fund
     Insurance Company


BY:  /s/ Jim Livingston                      BY: /s/ Robert C. Pozen
     ------------------------------             ----------------------------
      Jim Livingston                             Robert C. Pozen
      Executive Vice President                   Senior Vice President

                                           Fidelity Distributors Corporation



                                           BY: /s/ Kevin J. Kelly
                                               -----------------------------
                                                Kevin J. Kelly
                                                Vice President




                                   Schedule A
                                   ----------

                   Separate Accounts and Associated Contracts
                   ------------------------------------------

Name of Separate Account and                 Contracts Funded
Date of Established by Board of Directors    By Separate Account
- -----------------------------------------    -------------------

Security Life Separate Account A1            o   The Exchequer Variable Annuity
(November 3, 1993)                               (Flexible Premium Deferred
                                                 Combination Fixed and Variable
                                                 Annuity Contract)

Security Life Separate Account L1            o   First Line (Flexible Premium
(November 3, 1993)                               Variable Life Insurance Policy)
                                             o   Strategic Advantage Variable
                                                 Universal Life (Flexible
                                                 Premium Variable Universal Life
                                                 Insurance Policy)
                                             o   FirstLine II Variable Universal
                                                 Life (Flexible Premium Variable
                                                 Universal Life Insurance
                                                 Policy)
                                             o   Strategic Advantage II Variable
                                                 Universal Life (Flexible
                                                 Premium Variable Life
                                                 Insurance)
                                             o   Variable Survivorship Universal
                                                 Life (Flexible Premium Variable
                                                 Life Insurance)
                                             o   Corporate Benefits Variable
                                                 Universal Life (Flexible
                                                 Premium Variable Life
                                                 Insurance)
                                             o   Strategic Benefit Variable
                                                 Universal Life (Flexible
                                                 Premium Variable Life
                                                 Insurance)
                                             o   Estate Designer Variable
                                                 Universal Life (Joint and
                                                 Survivor Flexible Premium
                                                 Variable Life Insurance)





                                   Schedule C
                                   ----------

Other investment companies currently available under variable annuities or
variable life insurance issued by the Company (not al funds/portfolios are
available in all products):

                     AIM VI Capital Appreciation Portfolio
                     AIM VI Government Securities Portfolio

                     Alger American MidCap Growth Portfolio
                     Alger American Small Capitalization Portfolio
                     Alger American Growth Portfolio
                     Alger American Leveraged Allcap Portfolio

                     GCG Trust
                           Equity Income Portfolio
                           Growth Portfolio
                           Hard Assets Portfolio
                           Limited Maturity Bond Portfolio
                           Liquid Asset Portfolio
                           Mid-Cap Growth Portfolio
                           Research Portfolio
                           Total Return Portfolio

                     INVESCO VIF High Yield Fund
                     INVESCO VIF Equity Income Fund
                     INVESCO VIF Total Return Fund
                     INVESCO VIF Utilities Fund
                     INVESCO VIF Small Company Growth Fund

                     Neuberger Berman Growth Portfolio
                     Neuberger Berman Limited Maturity Bond Portfolio
                     Neuberger Berman Partners Portfolio

                     Van Eck Worldwide Insurance Trust
                           Worldwide Bond Fund
                           Worldwide Emerging Markets Fund
                           Worldwide Hard Assets Fund
                           Worldwide Real Estate Fund

                     Fidelity Investments Variable Insurance Products Fund II
                           Asset Manager Portfolio
                           Index 500






                                   Schedule D
                                   ----------

        Portfolios of the Fund available as funding vehicles under the
Contracts:

Initial Class Shares
        Growth Portfolio
        Money Market Portfolio
        Overseas Portfolio

Service Class Shares (Strategic Benefit Contracts only)
        Growth Portfolio
        Overseas Portfolio