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                                                                     EXHIBIT 4.3

                         PENTASTAR COMMUNICATIONS, INC.

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                           CERTIFICATE OF DESIGNATION
                                       OF
                            SERIES A PREFERRED STOCK

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First:

         The name of the corporation is PentaStar Communications, Inc.

Second:

         PentaStar Communications, Inc., a Delaware corporation, certifies that,
pursuant to authority granted to and vested in the Board of Directors of the
corporation by the provisions of the certificate of incorporation of the
corporation, the Board duly adopted, effective October 12, 1999, the following
resolution designating a series of the Preferred Stock of the corporation:

         RESOLVED: That there be created a series of Preferred Stock which shall
be designated as Series A Preferred Stock and shall have the powers,
preferences, rights, qualifications, limitations and restrictions set forth
below:

         1. Designation and Number. A series of Preferred Stock is hereby
established and designated the Series A Preferred Stock, par value $.0001 per
share (the "Series A Preferred Stock"). The number of shares which constitutes
the Series A Preferred Stock is 86 shares. Each share of the Series A Preferred
Stock shall have a stated value of $1,000 per share.

         2. Dividends.

                  (a) The holders of Series A Preferred Stock shall be entitled
to receive, when, as and if declared by the Board of Directors out of funds at
the time legally available therefor, dividends at the annual rate of $50.00 per
annum per share (i.e., a 5% annual rate on its $1,000 stated value), which shall
be fully cumulative, shall accrue from the date of initial issuance of each
share of Series A Preferred Stock (on a daily basis whether or not sufficient
funds would be legally available at that time for the payment of such dividends)
and shall be payable in cash annually in arrears on December 31 of each year in
respect of the 12-month period (or portion thereof during which such Preferred
Stock was outstanding) ending on such December 31 (except that if any such



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payment date is a Saturday, Sunday or legal holiday, then such dividend shall be
payable on the first preceding day that is not a Saturday, Sunday or legal
holiday). Each such dividend shall be paid to the holders of record of the
Series A Preferred Stock as they appear upon the stock transfer books of the
corporation at the close of business on such payment date. For purposes hereof,
the term "legal holiday" shall mean any day on which banking institutions are
authorized to close in Denver, Colorado. Dividends on account of arrears for any
past dividend period may be declared and paid at any time, without reference to
any regular dividend payment date.

                  (b) The corporation may elect to defer payment of dividends if
and to the extent the payment of such dividends would violate restrictions in
any loan agreement or indenture of the corporation or a subsidiary thereof
pursuant to which any of them then has indebtedness outstanding (such
restrictions being referred to as "Dividend Restrictions") or violate the
General Corporation Law of the State of Delaware (the "GCL"), and such dividends
so deferred will accumulate additional dividends as provided in Section 2(c).
Except as provided in the following sentence, such additional dividends will be
payable at the times referred to in Section 2(a). The corporation shall pay all
such deferred dividends and additional amounts accrued thereon, out of funds
then legally available therefor, as soon as, and to the extent that, such
payment does not violate the Dividend Restrictions or the GCL.

                  (c) Dividends whose payment is not made on a timely basis as
specified above (including, without limitation, all amounts referred to in
Section 2(b)) shall accumulate, together with an amount computed at the rate of
5% per annum thereon from the date such dividends were payable until paid in
full, compounded annually, which additional accrued amounts shall be paid as
additional dividends hereunder. In the event that the funds legally available
for dividends are not sufficient to pay the dividends accrued on the Series A
Preferred Stock, the funds available shall be paid to the holders of Preferred
Stock ratably in proportion to the respective unpaid dividends accrued on the
Series A Preferred Stock.

         3. Voting Rights. Except as otherwise provided by the GCL, the Series A
Preferred Stock will not be entitled to vote on any matters to be voted on by
the corporation's stockholders.

         4. Liquidation Preference.

                  (a) In the event of a liquidation, dissolution or winding up
of the corporation, whether voluntary or involuntary, the holders of shares of
Series A Preferred Stock shall be entitled to receive out of the assets of the
corporation available for distribution to stockholders an amount equal to the
dividends accrued and unpaid on such shares on the date of final distribution to
such holders, whether or not declared, including any accruals thereon provided
in Section 2(b) or (c), plus a sum equal to $1,000 per share, before any payment
shall be made or any assets distributed to the holders of shares of Common
Stock.

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                  (b) After payment in full of the liquidation preference of the
shares of the Series A Preferred Stock, any remaining assets of the corporation
available for distribution to the stockholders shall be distributed as set forth
in the corporation's certificate of incorporation.

                  (c) Any (i) transaction or event in connection with which the
Common Stock of the corporation shall be converted into or constitute solely the
right to receive cash, securities (other than solely equity securities of the
corporation), property or other assets (whether by means of an exchange offer,
consolidation, merger, combination, reclassification, recapitalization or
otherwise), (ii) conveyance, sale, lease, assignment, transfer or other
disposition of all or substantially all of the corporation's property, business
or assets, (iii) sale by the corporation or one or more of its stockholders in a
single transaction or series of related transactions of at least 50% of the
corporation's voting power after such sale or (iv) consolidation or merger of
the corporation with or into any other entity or entities where the corporation
is not the surviving entity (other than a merger solely for the purpose of
changing the corporation's state of incorporation) or in which 50% or more of
the corporation's voting power is transferred, shall be deemed to be a
liquidation, dissolution and winding up of the corporation within the meaning of
Section 4(a). The phrase "voting power" means general voting power under
ordinary circumstances to elect the board of directors of the corporation
(irrespective of whether or not at the time capital stock of any other class or
classes shall have or might have voting power by reason of the happening of any
contingency).

         5. Redemption or Call. No holder of Series A Preferred Stock may
require the corporation to redeem all or any part of the shares of Series A
Preferred Stock. The corporation may not call or redeem all or any part of the
shares of Series A Preferred Stock.

         6. Conversion. The shares of Series A Preferred Stock shall not be
convertible into Common Stock or any other capital stock of the corporation.

         7. Limitations. The corporation may, at any time the Series A Preferred
Stock is outstanding, authorize or issue any series of Preferred Stock that is
senior to or on parity with the Series A Preferred Stock as to dividend or
redemption rights, liquidation preferences or otherwise. So long as any shares
of Series A Preferred Stock remain outstanding, the corporation shall not,
directly or indirectly, without the written consent of the holders of a majority
of the then-outstanding shares of Series A Preferred Stock:

                  (a) Purchase, redeem or otherwise acquire for value (or pay
into or set aside as a sinking fund for such purpose) any Common Stock or any
warrant, option or right to purchase any Common Stock;

                  (b) At any time during which there are accrued dividends
outstanding on the Series A Preferred Stock, declare or pay any dividends on or
declare or make any other distribution, direct or indirect (other than a
dividend payable solely in shares of Common Stock), on account of the Common
Stock (or set apart any sum for any such purpose);

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         (c) Amend its Certificate of Incorporation or amend or repeal its
bylaws in any manner that would adversely affect the rights or preferences of
the Series A Preferred Stock; or

         (d) Issue any additional shares of Series A Preferred Stock.

Third:

         The foregoing resolution of the Board of Directors and creation and
authorization of the issuance of said series of Preferred Stock were duly made
by the Board of Directors pursuant to and in accordance with Section 151 of the
Delaware General Corporation Law.

         IN WITNESS WHEREOF, PentaStar Communications, Inc. has caused this
Certificate of Designation to be executed by Richard M. Tyler, its Vice
President, on this 21st day of October, 1999.



                                              PENTASTAR COMMUNICATIONS, INC.




                                              By: /s/ Richard M. Tyler
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                                                       Richard M. Tyler,
                                                       Vice President




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