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                                                                    Exhibit 3.l

                             KEYSTONE PROPERTY TRUST

                      ARTICLES SUPPLEMENTARY RECLASSIFYING
                      SERIES A CONVERTIBLE PREFERRED STOCK
                           AND FIXING DISTRIBUTION AND
                   OTHER PREFERENCES AND RIGHTS OF SUCH SERIES


      Keystone Property Trust, a Maryland statutory real estate trust, having
its principal office in the state of Maryland in the City of Baltimore (the
"TRUST"), hereby certifies to the State Department of Assessments and Taxation
of Maryland (the "Department") that:

      Pursuant to authority expressly vested in the Board of Trustees by Article
IV of the Declaration of Trust, the Board of Trustees adopted resolutions
reclassifying 800,000 Common Shares, par value $.001 per share, into a series of
Preferred Shares to be known as Series A Convertible Preferred Stock, par value
$.001 per share, and determined the preferences, conversion and other rights,
voting powers, restrictions, limitations as to dividends, qualifications, and
terms and conditions of redemption, number of shares and dividend rate of the
Series A Convertible Preferred Stock.

      Pursuant to such authority, Articles Supplementary were filed with the
Department on April 30, 1999. The within Articles Supplementary are being filed
before the issuance of any shares of Series A Convertible Preferred Stock so as
to modify the preferences, conversion and other rights, voting powers,
restrictions, limitations as to dividends, qualifications, and terms and
conditions of redemption, number of shares and dividend rate of the Series A
Convertible Preferred Stock.

      Immediately before the reclassification, there are 800,000 shares
classified as Series A Convertible Preferred Stock, and immediately after the
reclassification, there are 800,000 shares classified as Series A Convertible
Preferred Stock (with the preferences and rights of such series modified as set
forth herein).

      The preferences, conversion and other rights, voting powers, restrictions,
limitations as to dividends, qualifications, and terms and conditions of
redemption, number of shares and dividend rate of the Series A Convertible
Preferred Stock, as so modified and determined are as follows:

      SECTION 1. NUMBER OF SHARES AND DESIGNATION. This series of Preferred
Shares shall be designated as Series A Convertible Preferred Stock (the "Series
A Preferred Shares"), and the number of Preferred Shares which shall constitute
such series shall be 800,000 shares which number may be decreased (but not below
the number thereof then outstanding) from time to time by the Board of Trustees.

      SECTION 2.  DEFINITIONS.  For purposes of the Series A Preferred
Shares, the

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following terms shall have the meanings indicated:

      "Act" shall mean the Securities Act of 1933, as amended.

      "Board of Trustees" shall mean the Board of Trustees of the Trust or any
committee authorized by such Board of Trustees to perform any of its
responsibilities with respect to the Series A Preferred Shares.

      "Business Day" shall mean any day other than a Saturday, Sunday or a day
on which state or federally chartered banking institutions in New York, New York
are not required to be open.

      "Change in Control" shall mean any merger or consolidation of the Trust in
which one or more entities which are not affiliates of the Trust acquire more
than 50% of the Trust's outstanding voting equity securities or as a result of
which shareholders of the Trust immediately before such merger or consolidation
hold, immediately after such merger or consolidation, less than 50% of the
surviving entity's outstanding common shares.

      "Common Shares" shall mean the common shares, par value $.001 per share,
of the Trust.

      "Constituent Person" shall have the meaning set forth in paragraph (e) of
Section 7 hereof.

      "Continuation Right" shall have the meaning set forth in Section 4.

      "Conversion Price" shall mean the conversion price per Common Share for
which each Series A Preferred Share is convertible, as such Conversion Price may
be adjusted pursuant to Section 7 hereof. The initial conversion price shall be
$16.50 (equivalent to a conversion rate of 1.51515 Common Shares for each Series
A Preferred Share).

      "Current Market Price" shall mean, with respect to the Common Shares, on
any date specified herein, the average of the Market Price during the period of
the most recent ten consecutive trading days ending on such date.

      "Declaration" shall mean the Trust's Declaration of Trust and any
amendments or supplements thereto.

      "Dividend Payment Date" shall mean, with respect to each Dividend Period,
the last calendar day of January, April, July and October, in each year,
commencing on January 31, 1999; provided, however, that if any Dividend Payment
Date falls on any day other than a Business Day, the dividend payment due on
such Dividend Payment Date shall be paid on the first Business Day immediately
following such Dividend Payment Date.

      "Dividend Periods" shall mean quarterly dividend periods commencing on
February 1,


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May 1, August 1 and November 1 of each year and ending on and including the day
preceding the first day of the next succeeding Dividend Period (other than the
initial Dividend Period, which shall commence on the Issue Date and end on and
include January 31, 1999).

      "Issue Date" shall mean the first date on which any Series A Preferred
Shares are issued and sold.

      "Junior Shares" shall mean the Common Shares and any other class or series
of shares of beneficial interest of the Trust constituting junior shares within
the meaning set forth in paragraph (c) of Section 9 hereof.

      "Liquidation" shall mean (A) a dissolution or winding up of the Trust,
whether voluntary or involuntary, (B) a consolidation or merger of the Trust
with and into one or more entities which are not affiliates of the Trust which
results in a Change in Control, or (C) a sale or transfer of all or
substantially all of the Trust's assets other than to an affiliate of the Trust.

      "Liquidation Preference" shall have the meaning set forth in Section 4
hereof.

      "Liquidation Premium" shall mean (X) on or prior to December 15, 2003, in
connection with (i) a Merger Liquidation in which the surviving entity is a
Qualified Entity, an amount equal to five percent (5%) of the Liquidation
Preference or (ii) any other Liquidation, an amount equal to ten percent (10%)
of the Liquidation Preference, or (Y) after December 15, 2003, in connection
with any Liquidation, an amount equal to the Redemption Premium set forth in
Section 5.

      "Market Price" shall mean, with respect to the Common Shares on any date,
the last reported sales price, regular way on such day, or, in case no such sale
takes place on such day, the average of the closing bid and asked prices,
regular way on such day, in either case as reported in the principal
consolidated transaction reporting system with respect to securities listed or
admitted to trading on the American Stock Exchange ("AMEX") or, if the Common
Shares are not listed or admitted for trading on AMEX, as reported in the
principal consolidated transaction reporting system with respect to securities
listed on the principal national securities exchange on which the Common Shares
are listed or admitted for trading or, if the Common Shares are not listed or
admitted for trading on any national securities exchange, the last quoted price,
or if not so quoted, the average of the high bid and low asked prices in the
over-the-counter market, as reported by the NASD Automated Quotation System or,
if such system is no longer in use, the principal other automated quotation
system that may then be in use, or if the Common Shares are not quoted by any
such organization, the average of the closing bid and asked prices as furnished
by a professional market maker regularly making a market in the Common Shares
selected for such purpose by the Board of Trustees or, if there is no such
professional market maker, such amount as an independent investment banking firm
selected by the Board of Trustees determines to be the value of a Common Share.


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      "Merger Liquidation" shall have the meaning set forth in Section 4.

      "Non-Electing Share" shall have the meaning set forth in paragraph (e) of
Section 7 hereof.

      "Parity Shares" shall have the meaning set forth in paragraph (b) of
Section 9 hereof.

      "Person" shall mean any individual, firm, partnership, corporation, trust,
limited liability company or other entity, and shall include any successor (by
merger or otherwise) of such entity.

      "Preferred Shares" shall mean the preferred shares, par value $.001 per
share, of the Trust.

      "Qualified Entity" shall mean any Person that (I) either (i) is or may be
the issuer of senior unsecured debt securities which are rated no lower than
investment grade by either Standard & Poor's Rating Service, Inc., a division of
the McGraw Hill Companies, Inc. ("S&P"), or Moody's Investor Services, Inc.
("Moody's"), which rating may (A) relate to any outstanding issue of such debt
securities or (B) relate to any unissued debt securities registered on an
effective shelf registration statement or (ii) is an issuer of outstanding
preferred equity securities which are rated no lower than Ba1 by Moody's or BB+
by S&P, and (II) is the issuer of common equity securities the average daily
trading volume of which on the principal national securities exchange on which
such common equity securities are traded on the 30 most recent Trading Days has
been equal to or greater than $2,475,000 per day.

      "Qualifying Offering" shall mean the sale of Common Shares in an
underwritten public offering (in which no person acquires more than 10% of the
Common Shares to be sold) at a price of at least $16.50 per share which results
in net proceeds to the REIT of at least $150 million.

      "Redemption Date" shall have the meaning set forth in paragraph (a) of
Section 5 hereof.

      "Redemption Notice" shall have the meaning set forth in paragraph (a) of
Section 5 hereof.

      "Redemption Premium" shall have the meaning set forth in paragraph (a) of
Section 5 hereof.

      "Securities" shall have the meaning set forth in paragraph (d)(iii) of
Section 7 hereof.

      "Series A Preferred Shares" shall have the meaning set forth in Section 1
hereof.

      "Set apart for payment" shall be deemed to include, without any action
other than the


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following, the recording by the Trust in its accounting ledgers of any
accounting or bookkeeping entry which indicates, pursuant to a declaration of a
dividend or other distribution by the Board of Trustees, the allocation of funds
to be so paid on any series or class of shares of beneficial interest of the
Trust; provided, however, that if any funds for any class or series of Junior
Shares or any class or series of Parity Shares are placed in a separate account
of the Trust or delivered to a disbursing, paying or other similar agent, then
"set apart for payment" with respect to the Series A Preferred Shares shall mean
placing such funds in a separate account or delivering such funds to a
disbursing, paying or other similar agent.

      "Trading Day" shall mean any day on which the securities in question are
traded on the New York Stock Exchange ("NYSE"), or if such securities are not
listed or admitted for trading on the NYSE, on the principal national securities
exchange on which such securities are listed or admitted, or if not listed or
admitted for trading on any national securities exchange, on the Nasdaq National
Market, or if such securities are not quoted on such Nasdaq National Market, in
the applicable securities market in which the securities are traded.

      "Transaction" shall have the meaning set forth in paragraph (e) of Section
7 hereof.

      "Voting Preferred Shares" shall have the meaning set forth in Section 10
hereof.

      SECTION 3.  DIVIDENDS.

            (a) The holders of Series A Preferred Shares shall be entitled to
receive, when, as and if authorized and declared by the Board of Trustees out of
funds legally available for that purpose, dividends payable in cash at the rate
per annum equal to the greater of (i) $2.25 per Series A Preferred Share or (ii)
an amount per Series A Preferred Share equal to the aggregate annual amount of
cash dividends paid or payable, if any, with respect to that number of Common
Shares, or portion thereof, into which each Series A Preferred Share is then
convertible, in accordance with the terms of these Articles Supplementary (such
greater amount, the ("Annual Dividend Rate"). The amount referred in clause (ii)
of this subparagraph (a) with respect to each Dividend Period shall be
determined as of the applicable Dividend Payment Date by multiplying the number
of Common Shares, or portion thereof calculated to the fourth decimal point,
into which a Series A Preferred Share would be convertible at the opening of
business on such Dividend Payment Date (based on the Conversion Price then in
effect) by the quarterly cash dividend payable or paid for such Dividend Period
in respect of a Common Share outstanding as of the record date for the payment
of dividends on the Common Shares with respect to such Dividend Period or, if
different, with respect to the most recent quarterly period for which dividends
with respect to the Common Shares have been declared. Such dividends shall be
cumulative from the Issue Date, whether or not in any Dividend Period or Periods
there shall be funds of the Trust legally available for the payment of such
dividends, shall compound quarterly at a rate per annum equal to nine percent
(9%) and shall be payable quarterly, when, as and if authorized and declared by
the Board of Trustees, in arrears on Dividend Payment Dates, commencing on the
first Dividend Payment Date after the Issue Date. Each such dividend shall


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be payable in arrears to the holders of record of the Series A Preferred Shares,
as they appear on the share records of the Trust at the close of business on
each record date which shall not be more than 30 days preceding the applicable
Dividend Payment Date (the "Dividend Payment Record Date"), as shall be fixed by
the Board of Trustees. Accrued and unpaid dividends for any past Dividend
Periods may be authorized and declared and paid at any time, without reference
to any regular Dividend Payment Date, to holders of record on such date, which
shall not be more than 45 days preceding the payment date thereof, as may be
fixed by the Board of Trustees. The amount of accrued and unpaid dividends on
any Series A Preferred Share at any date shall be the amount of any dividends
thereon calculated and compounded at the applicable rate to and including such
date, whether or not earned or declared, which have not been paid in cash.

            (b) The amount of dividends payable for each full Dividend Period
for the Series A Preferred Shares shall be computed by dividing the Annual
Dividend Rate by four. The amount of dividends payable for the initial Dividend
Period, or any other period shorter or longer than a full Dividend Period, on
the Series A Preferred Shares shall be computed on the basis of twelve 30-day
months and a 360-day year. Holders of Series A Preferred Shares shall not be
entitled to any dividends, whether payable in cash, property or shares, in
excess of cumulative dividends, as herein provided, on the Series A Preferred
Shares, plus any other amounts provided in these Articles Supplementary.

            (c) So long as any Series A Preferred Shares are outstanding, no
dividends, except as described in the immediately following sentence, shall be
authorized and declared or paid or set apart for payment on any series or class
or classes of Parity Shares for any period unless full cumulative dividends have
been or contemporaneously are authorized and declared and paid or authorized and
declared and a sum sufficient for the payment thereof set apart for such payment
on the Series A Preferred Shares for all Dividend Periods terminating on or
prior to the dividend payment date for such class or series of Parity Shares.
When dividends are not paid in full or a sum sufficient for such payment is not
set apart, as aforesaid, all dividends authorized and declared upon Series A
Preferred Shares and all dividends authorized and declared upon any other series
or class or classes of Parity Shares shall be authorized and declared ratably in
proportion to the respective amounts of dividends accumulated and unpaid on the
Series A Preferred Shares and such Parity Shares.

            (d) So long as any Series A Preferred Shares are outstanding, no
dividends (other than dividends or distributions paid solely in shares of, or
options, warrants or rights to subscribe for or purchase shares of, Junior
Shares) shall be authorized and declared or paid or set apart for payment or
other distribution authorized and declared or made upon Junior Shares, nor shall
any Junior Shares be redeemed, purchased or otherwise acquired (other than a
redemption, purchase or other acquisition of Common Shares made for purposes of
and in compliance with requirements of an employee incentive or benefit plan of
the Trust or any subsidiary), for any consideration (or any moneys to be paid to
or made available for a sinking fund for the redemption of any shares) by the
Trust, directly or indirectly (except by conversion into or


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exchange for Junior Shares), unless in each case (i) the full cumulative
dividends on all outstanding Series A Preferred Shares and any other Parity
Shares of the Trust shall have been paid or set apart for payment for all past
Dividend Periods with respect to the Series A Preferred Shares and all past
dividend periods with respect to such Parity Shares and (ii) sufficient funds
shall have been paid or set apart for the payment of the dividend for the
current Dividend Period with respect to the Series A Preferred Shares and any
Parity Shares.

      SECTION 4.  LIQUIDATION PREFERENCE.

            (a) In the event of any Liquidation, before any payment or
distribution of the assets of the Trust (whether capital or surplus) shall be
made to or set apart for the holders of Junior Shares, the holders of Series A
Preferred Shares shall be entitled (subject to the Continuation Right of such
holders described below) to receive an amount equal to the greater of (i) (A)
Twenty-Five Dollars ($25.00) per Series A Preferred Share plus dividends
(whether or not earned or declared) accrued and unpaid thereon to the date of
final distribution to such holder (the "Liquidation Preference") plus (B) the
Liquidation Premium or (ii) an amount per Series A Preferred Share equal to the
amount which would have been payable had each Series A Preferred Share been
converted into Common Shares immediately prior to such Liquidation. The
foregoing amounts shall be subject to equitable adjustment whenever there shall
occur a share dividend, share split, combination, reorganization,
recapitalization, reclassification or other similar event involving a change in
the capital structure of the Series A Preferred Shares. Until the holders of the
Series A Preferred Shares have been paid the Liquidation Preference in full, no
payment will be made to any holder of Junior Shares upon Liquidation. If, upon
any such Liquidation, the assets of the Trust, or proceeds thereof,
distributable among the holders of Series A Preferred Shares shall be
insufficient to pay in full the preferential amount aforesaid and liquidating
payments on any other class or series of Parity Shares, then such assets, or the
proceeds thereof, shall be distributed among the holders of such Series A
Preferred Shares and such other Parity Shares ratably in accordance with the
amounts that would be payable on such Series A Preferred Shares and such other
Parity Shares if all amounts payable thereon were paid in full.

In connection with a Merger Liquidation, the holders of Series A Preferred
Shares shall have the right (a "Continuation Right") to elect, by delivering
written notice to the Trust not less than five Business Days prior to the Merger
Liquidation, to require the Trust to make provision for the Series A Preferred
Shares to be assumed by the surviving entity as described in Section 7(e);
provided, however, notwithstanding the election by the holders of the Series A
Preferred Shares of the Continuation Right, the Trust shall have the right, in
connection with any Merger Liquidation, to elect, by delivering written notice
to the holders of Series A Preferred Shares at any time prior to the Merger
Liquidation, to redeem any or all of the outstanding Series A Preferred Shares
for an amount per Series A Preferred Share equal to the Liquidation Preference
plus a premium equal to ten percent (10%) of the Liquidation Preference. A
"Merger Liquidation" shall be a Liquidation which constitutes a consolidation or
merger of the Trust with one or more entities that are not affiliates of the
Trust and as a result of which the Trust is not the


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Surviving Entity.

            (b) Subject to the rights of the holders of any Parity Shares, upon
any Liquidation of the Trust, after payment shall have been made in full to the
holders of Series A Preferred Shares and any Parity Shares, as provided in this
Section 4, any other series or class or classes of Junior Shares shall, subject
to the respective terms thereof, be entitled to receive any and all assets
remaining to be paid or distributed, and the holders of the Series A Preferred
Shares and any Parity Shares shall not be entitled to share therein.

      SECTION 5.  REDEMPTION AT THE OPTION OF THE TRUST.

            (a) The Series A Preferred Shares shall not be redeemable by the
Trust prior to December 15, 2003. On and after December 15, 2003, the Trust, at
its option, may redeem the Series A Preferred Shares, in whole but not in part,
as set forth herein, subject to the provisions described below.

At any time on or after December 15, 2003, upon the written election of the
Trust given to each record holder of Series A Preferred Shares (the "Redemption
Notice"), the Trust may redeem for cash on the date specified in the Redemption
Notice (which date shall not be less than 20 days nor more than 30 days after
the date of the Redemption Notice) (the "Redemption Date"), all, but not less
than all, of the outstanding Series A Preferred Shares at a price per Series A
Preferred Share equal to the Liquidation Preference plus a premium (the
"Redemption Premium") which shall equal the following percentages of the
Liquidation Preference during in the following periods:

      From December 15, 2003 through and
      including December 14, 2004 ................................    4.5%

      From December 15, 2004 through and
      including December 14, 2005 ................................  3.375%

      From December 15, 2005 through and
      including December 14, 2006 ................................   2.25%

      From December 15, 2006 through and
      including December 14, 2007 ................................  1.125%

      December 15, 2007 and thereafter ...........................      0%


            (b) From and after the Redemption Date, (i) except as otherwise
provided herein, dividends on the Series A Preferred Shares so called for
redemption shall cease to accrue, (ii) said shares shall no longer be deemed to
be outstanding, and (iii) all rights of the holders thereof as holders of Series
A Preferred Shares of the Trust shall cease (except the rights to receive the
cash payable upon such redemption, without interest thereon, upon surrender and


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endorsement of their certificates if so required and to receive any dividends
payable thereon). The Trust's obligation to provide cash in accordance with the
preceding sentence shall be deemed fulfilled if, on or before the Redemption
Date, the Trust shall deposit with a bank or trust company (which may be an
affiliate of the Trust) that has an office in the Borough of Manhattan, City of
New York, or in Philadelphia, Pennsylvania and that has, or is an affiliate of a
bank or trust company that has, a capital and surplus of at least $50,000,000,
any cash necessary for such redemption, in trust, with irrevocable instructions
that such cash be applied to the redemption of the Series A Preferred Shares so
called for redemption. No interest shall accrue for the benefit of the holder of
Series A Preferred Shares to be redeemed on any cash so set aside by the Trust.

      SECTION 6. REACQUIRED SHARES TO BE RETIRED. All Series A Preferred Shares
which shall have been issued and reacquired in any manner by the Trust shall be
restored to the status of authorized but unissued Series A Preferred Shares.

      SECTION 7. CONVERSION. Holders of Series A Preferred Shares shall have the
right to convert all or a portion of such shares into Common Shares, as follows:

            (a) Subject to and upon compliance with the provisions of this
Section 7, a holder of Series A Preferred Shares shall have the right, at his or
her option, at any time and from time to time, to convert such shares into the
number of fully paid and non-assessable Common Shares obtained by dividing the
aggregate Liquidation Preference of such Series A Preferred Shares by the
Conversion Price (as in effect at the time and on the date provided for in the
last paragraph of paragraph (b) of this Section 7) by surrendering such Series A
Preferred Shares to be converted, such surrender to be made in the manner
provided in paragraph (b) of this Section 7; provided, however, that the right
to convert Series A Preferred Shares called for redemption pursuant to Section 5
hereof shall terminate at the close of business on the Redemption Date fixed for
such redemption, unless the Trust shall default in making payment of any cash
payable upon such redemption under Section 5 hereof.

            (b) In order to exercise the conversion right, the holder of each
Series A Preferred Share to be converted shall surrender the certificate
representing such Series A Preferred Share, duly endorsed or assigned to the
Trust or in blank, to the Trust, accompanied by written notice to the Trust that
the holder thereof elects to convert such Series A Preferred Shares. Unless the
Common Shares issuable on conversion are to be issued in the same name as the
name in which such Series A Preferred Shares are registered, each share
surrendered for conversion shall be accompanied by instruments of transfer, in
form satisfactory to the Trust, duly executed by the holder or such holder's
duly authorized attorney and an amount sufficient to pay any transfer or similar
tax (or evidence reasonably satisfactory to the Trust demonstrating that such
taxes have been paid).

Holders of Series A Preferred Shares at the close of business on any Dividend
Payment Record Date shall be entitled to receive the dividend payable on such
shares on the corresponding Dividend Payment Date notwithstanding the conversion
thereof (and of any accrued and unpaid


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dividends to the date or conversion) following such Dividend Payment Record Date
and prior to such Dividend Payment Date. However, Series A Preferred Shares
surrendered for conversion during the period between the close of business on
any Dividend Payment Record Date and the opening of business on the
corresponding Dividend Payment Date (except shares converted after the issuance
of a Redemption Notice with respect to a Redemption Date during such period,
such Series A Preferred Shares being entitled to such dividend on the Dividend
Payment Date) must be accompanied by payment of an amount equal to the dividend
payable on such shares on such Dividend Payment Date. A holder of Series A
Preferred Shares on a Dividend Payment Record Date who (or whose transferee)
tenders any such shares for conversion into Common Shares on such Dividend
Payment Date will receive the dividend payable by the Trust on such Series A
Preferred Shares on such date, and the converting holder need not include
payment of the amount of such dividend upon surrender of Series A Preferred
Shares for conversion.

As promptly as practicable after the surrender of certificates for Series A
Preferred Shares as aforesaid, the Trust shall issue and shall deliver at such
office to such holder, or send on his or her written order, a certificate or
certificates for the number of full Common Shares issuable upon the conversion
of such Series A Preferred Shares in accordance with the provisions of this
Section 7, and any fractional interest in respect of a Common Share arising upon
such conversion shall be settled as provided in paragraph (c) of this Section 7.

Each conversion shall be deemed to have been effected immediately prior to the
close of business on the date on which the certificates for Series A Preferred
Shares shall have been surrendered and such notice received by the Trust as
aforesaid, and the person or persons in whose name or names any certificate or
certificates for Common Shares shall be issuable upon such conversion shall be
deemed to have become the holder or holders of record of the Common Shares
represented thereby at such time on such date, and such conversion shall be at
the Conversion Price in effect at such time and on such date unless the share
transfer books of the Trust shall be closed on that date, in which event such
person or persons shall be deemed to have become such holder or holders of
record at the close of business on the next succeeding day on which such share
transfer books are open, but such conversion shall be at the Conversion Price in
effect on the date on which such Series A Preferred Shares shall have been
surrendered and such notice received by the Trust.

            (c) No fractional shares or scrip representing fractions of Common
Shares shall be issued upon conversion of the Series A Preferred Shares. Instead
of any fractional interest in a Common Share that would otherwise be deliverable
upon the conversion of a Series A Preferred Share, the Trust shall pay to the
holder of such Series A Preferred Share an amount in cash based upon the Current
Market Price of Common Shares on the Trading Day immediately preceding the date
of conversion. If more than one Series A Preferred Share shall be surrendered
for conversion at one time by the same holder, the number of full Common Shares
issuable upon conversion thereof shall be computed on the basis of the aggregate
number of Series A Preferred Shares so surrendered.


                                     - 10 -
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            (d)   The Conversion  Price shall be adjusted from time to time as
follows:

                  (i) If the Trust shall after the Issue Date (A) pay a dividend
or make a distribution on its shares of beneficial interest in Common Shares,
(B) subdivide its outstanding Common Shares into a greater number of shares, (C)
combine its outstanding Common Shares into a smaller number of shares or (D)
issue any shares of beneficial interest by reclassification of its Common
Shares, the Conversion Price in effect at the opening of business on the day
following the date fixed for the determination of shareholders entitled to
receive such dividend or distribution or at the opening of business on the day
following the day on which such subdivision, combination or reclassification
becomes effective, as the case may be, shall be adjusted so that the holder of
any Series A Preferred Share thereafter surrendered for conversion shall be
entitled to receive the number of Common Shares that such holder would have
owned or have been entitled to receive after the happening of any of the events
described above, had such Series A Preferred Share been converted immediately
prior to the record date in the case of a dividend or distribution or the
effective date in the case of a subdivision, combination or reclassification. An
adjustment made pursuant to this subparagraph (i) shall become effective
immediately upon the opening of business on the day next following the record
date (subject to paragraph (h) below) in the case of a dividend or distribution
and shall become effective immediately upon the opening of business on the day
next following the effective date in the case of a subdivision, combination or
reclassification.

                  (ii) If the Trust shall issue after the Issue Date rights,
options or warrants to all holders of Common Shares entitling them (for a period
expiring within 45 days after the record date mentioned below in this
subparagraph (ii)) to subscribe for or purchase Common Shares at a price per
share less than the Current Market Price per Common Share on the record date for
the determination of shareholders entitled to receive such rights, options or
warrants, then the Conversion Price in effect at the opening of business on the
day next following such record date shall be adjusted to equal the price
determined by multiplying (A) the Conversion Price in effect immediately prior
to the opening of business on the day following the date fixed for such
determination by (B) a fraction, the numerator of which shall be the sum of (I)
the number of Common Shares outstanding on the close of business on the date
fixed for such determination and (II) the number of Common Shares that the
aggregate proceeds to the Trust from the exercise of such rights, options or
warrants for Common Shares would purchase at such Current Market Price, and the
denominator of which shall be the sum of (I) the number of Common Shares
outstanding on the close of business on the date fixed for such determination
and (II) the number of additional Common Shares offered for subscription or
purchase pursuant to such rights, options or warrants. Such adjustment shall
become effective immediately upon the opening of business on the day next
following such record date (subject to paragraph (h) below). In determining
whether any rights, options or warrants entitle the holders of Common Shares to
subscribe for or purchase Common Shares at less than such Current Market Price,
there shall be taken into account any consideration received by the Trust upon
issuance and upon exercise of such rights, options or warrants, the value of
such consideration, if other than cash, to be determined by the Chief Executive
Officer or the Board of Trustees, whose determination


                                     - 11 -
<PAGE>


shall be conclusive.

                  (iii) If the Trust shall distribute to all holders of its
Common Shares any shares of beneficial interest of the Trust (other than Common
Shares) or evidence of its indebtedness or assets (excluding cash dividends or
distributions paid out of assets based upon a fair valuation of the assets, in
excess of the sum of the liabilities of the Trust and the amount of stated
capital attributable to Common Shares, determined on the basis of the most
recent annual consolidated cost basis and current value basis and quarterly
consolidated balance sheets of the Trust and its consolidated subsidiaries
available at the time of the declaration of the dividend or distribution) or
rights or warrants to subscribe for or purchase any of its securities (excluding
those rights and warrants issued to all holders of Common Shares entitling them
for a period expiring within 45 days after the record date referred to in
subparagraph (ii) above to subscribe for or purchase Common Shares, which rights
and warrants are referred to in and treated under subparagraph (ii) above) (any
of the foregoing being hereinafter in this subparagraph (iii) called the
"Securities"), then in each case the Conversion Price shall be adjusted so that
it shall equal the price determined by multiplying (A) the Conversion Price in
effect immediately prior to the close of business on the date fixed for the
determination of shareholders entitled to receive such distribution by (B) a
fraction, the numerator of which shall be the Current Market Price per Common
Share on the record date mentioned below less the then fair market value (as
determined by the Board of Trustees, whose determination shall be conclusive) of
the portion of the shares of beneficial interest or assets or evidences of
indebtedness so distributed or of such rights or warrants applicable to one
Common Share, and the denominator of which shall be the Current Market Price per
Common Share on the record date mentioned below. Such adjustment shall become
effective immediately upon the opening of business on the day next following
(subject to paragraph (h) below) the record date for the determination of
shareholders entitled to receive such distribution. For the purposes of this
subparagraph (iii), the distribution of a Security, which is distributed not
only to the holders of the Common Shares on the date fixed for the determination
of shareholders entitled to such distribution of such Security, but also is
required to be distributed with each Common Share delivered to a Person
converting a Series A Preferred Share after such determination date, shall not
require an adjustment of the Conversion Price pursuant to this subparagraph
(iii); provided that on the date, if any, on which a person converting a Series
A Preferred Share would no longer be entitled to receive such Security with a
Common Share (other than as a result of the termination of all such Securities),
a distribution of such Securities shall be deemed to have occurred, and the
Conversion Price shall be adjusted as provided in this subparagraph (iii) (and
such day shall be deemed to be "the date fixed for the determination of the
shareholders entitled to receive such distribution" and "the record date" within
the meaning of the two preceding sentences).

The occurrence of a distribution or the occurrence of any other event as a
result of which holders of Series A Preferred Shares shall not be entitled to
receive rights, including exchange rights (the "Rights"), pursuant to any
shareholders protective rights agreement (the "Agreement") that may be adopted
by the Trust as if such holders had converted such shares into Common Shares
immediately prior to the occurrence of such distribution or event shall not be
deemed a


                                     - 12 -
<PAGE>


distribution of Securities for the purposes of any Conversion Price adjustment
pursuant to this subparagraph (iii) or otherwise give rise to any Conversion
Price adjustment pursuant to this Section 7; provided, however, that in lieu of
any adjustment to the Conversion Price as a result of any such a distribution or
occurrence, the Trust shall make provision so that Rights, to the extent
issuable at the time of conversion of any Series A Preferred Shares into Common
Shares, shall issue and attach to such Common Shares then issued upon conversion
in the amount and manner and to the extent and as provided in the Agreement in
respect of issuances at the time of Common Shares other than upon conversion.

                  (iv) No adjustment in the Conversion Price shall be required
unless such adjustment would require a cumulative increase or decrease of at
least 1% in such price; provided, however, that any adjustments that by reason
of this subparagraph (iv) are not required to be made shall be carried forward
and taken into account in any subsequent adjustment until made; and provided,
further, that any adjustment shall be required and made in accordance with the
provisions of this Section 7 (other than this subparagraph (iv)) not later than
such time as may be required in order to preserve the tax-free nature of a
distribution to the holders of Common Shares. Notwithstanding any other
provisions of this Section 7, the Trust shall not be required to make any
adjustment of the Conversion Price for the issuance of any Common Shares
pursuant to any plan providing for the reinvestment of dividends or interest
payable on securities of the Trust and the investment of additional optional
amounts in Common Shares under such plan. All calculations under this Section 7
shall be made to the nearest cent (with $.005 being rounded upward) or to the
nearest one-tenth of a share (with .05 of a share being rounded upward), as the
case may be. Anything in this paragraph (d) to the contrary notwithstanding, the
Trust shall be entitled, to the extent permitted by law, to make such reductions
in the Conversion Price, in addition to those required by this paragraph (d), as
it in its discretion shall determine to be advisable in order that any share
dividends, subdivision of shares, reclassification or combination of shares,
distribution of rights, options or warrants to purchase shares or securities, or
a distribution of other assets (other than cash dividends) hereafter made by the
Trust to its shareholders shall not be taxable.

            (e)   If the Trust shall be a party to any transaction (including
without limitation a merger, consolidation, statutory share exchange, self
tender offer for all or substantially all Common Shares outstanding, sale of all
or substantially all of the Trust's assets or recapitalization of the Common
Shares but excluding any transaction as to which subparagraph (d)(i) of this
Section 7 applies) (each of the foregoing being referred to herein as a
"Transaction"), in each case as a result of which Common Shares shall be
converted into the right to receive shares, securities or other property
(including cash or any combination thereof), each Series A Preferred Share that
is not redeemed or converted into the right to receive shares, securities or
other property in connection with such Transaction shall thereafter be
convertible into the kind and amount of shares, securities and other property
(including cash or any combination thereof) receivable upon the consummation of
such Transaction by a holder of that number of Common Shares into which one
Series A Preferred Share was convertible immediately prior to such Transaction,
assuming such holder of Common Shares (i) is not a


                                     - 13 -
<PAGE>


Person with which the Trust consolidated or into which the Trust merged or which
merged into the Trust or to which such sale or transfer was made, as the case
may be (a "Constituent Person"), or an affiliate of a Constituent Person and
(ii) failed to exercise his or her rights of the election, if any, as to the
kind or amount of shares, securities and other property (including cash)
receivable upon such Transaction (provided that if the kind or amount of shares,
securities and other property (including cash) receivable upon such Transaction
is not the same for each Common Share of the Trust held immediately prior to
such Transaction by other than a Constituent Person or an affiliate thereof and
in respect of which such rights of election shall not have been exercised
("Non-Electing Share"), then for the purpose of this paragraph (e) the kind and
amount of shares, securities and other property (including cash) receivable upon
such Transaction by each Non-Electing Share shall be deemed to be the kind and
amount so receivable per share by a plurality of the Non-Electing Shares). The
Trust shall not be a party to any Transaction unless the terms of such
Transaction are consistent with the provisions of this paragraph (e), and it
shall not consent or agree to the occurrence of any Transaction until the Trust
has entered into an agreement with the successor or purchasing entity, as the
case may be, for the benefit of the holders of the Series A Preferred Shares
that will contain provisions enabling the holders of the Series A Preferred
Shares that remain outstanding after such Transaction to convert their Series A
Preferred Shares into the consideration received by holders of Common Shares at
the Conversion Price in effect immediately prior to such Transaction. The
provisions of this paragraph (e) shall similarly apply to successive
Transactions.

            (f)   If:

                  (i) the Trust shall declare a dividend (or any other
distribution) on the Common Shares (other than in cash out of assets, based on a
fair valuation of assets, in excess of the sum of the liabilities of the Trust
and the amount of stated capital attributable to Common Shares, determined on
the basis of the most recent annual consolidated cost basis and current value
basis and quarterly consolidated balance sheets of the Trust and its
consolidated subsidiaries available at the time of the declaration of the
dividend or distribution); or

                  (ii) the Trust shall authorize the granting to the holders of
the Common Shares of rights or warrants to subscribe for or purchase any shares
of any class or any other rights or warrants (other than Rights to which the
second paragraph of subparagraph (d)(iii) of this Section 7 applies); or

                  (iii) there shall be any reclassification of the Common Shares
(other than an event to which subparagraph (d) (i) of this Section 7 applies) or
any consolidation or merger to which the Trust is a party and for which approval
of any shareholders of the Trust is required, or a statutory share exchange
involving the conversion or exchange of Common Shares into securities or other
property, or a self tender offer by the Trust for all or substantially all of
its outstanding Common Shares, or the sale or transfer of all or substantially
all of the assets of the Trust as an entirety and for which approval of any
shareholders of the Trust is required; or


                                     - 14 -
<PAGE>


                  (iv)  there  shall  occur  the   voluntary  or   involuntary
liquidation, dissolution or winding up of the Trust,

then the Trust shall cause to be prepared and delivered to the holders of the
Series A Preferred Shares at their addresses as shown on the share records of
the Trust, as promptly as possible, but at least 15 days prior to the applicable
date hereinafter specified, a notice stating (A) the date on which a record is
to be taken for the purpose of such dividend, distribution or rights or
warrants, or, if a record is not to be taken, the date as of which the holders
of Common Shares of record to be entitled to such dividend, distribution or
rights or warrants are to be determined or (B) the date on which such
reclassification, consolidation, merger, statutory share exchange, sale,
transfer, liquidation, dissolution or winding up is expected to become
effective, and the date as of which it is expected that holders of Common Shares
of record shall be entitled to exchange their Common Shares for securities or
other property, if any, deliverable upon such reclassification, consolidation,
merger, statutory share exchange, sale, transfer, liquidation, dissolution or
winding up. Failure to give or receive such notice or any defect therein shall
not affect the legality or validity of the proceedings described in this Section
7.

            (g) Whenever the Conversion Price is adjusted as herein provided,
the Trust shall promptly prepare and deliver to the holders of the Series A
Preferred Shares a notice of such adjustment of the Conversion Price setting
forth the adjusted Conversion Price and the effective date of such adjustment
and an officer's certificate setting forth the Conversion Price after such
adjustment and setting forth a brief statement of the facts requiring such
adjustment. The Trust shall mail such notice and such certificate to the holders
of each Series A Preferred Share at such holder's last address as shown on the
share records of the Trust.

            (h) In any case in which paragraph (d) of this Section 7 provides
that an adjustment shall become effective on the day next following the record
date for an event, the Trust may defer until the occurrence of such event (A)
issuing to the holder of any Series A Preferred Share converted after such
record date and before the occurrence of such event the additional Common Shares
issuable upon such conversion by reason of the adjustment required by such event
over and above the Common Shares issuable upon such conversion before giving
effect to such adjustment and (B) paying to such holder any amount of cash in
lieu of any fraction pursuant to paragraph (c) of this Section 7.

            (i) There shall be no adjustment of the Conversion Price in case of
the issuance of any shares of beneficial interest of the Trust in a
reorganization, acquisition or other similar transaction except as specifically
set forth in this Section 7. If any action or transaction would require
adjustment of the Conversion Price pursuant to more than one paragraph of this
Section 7, only one adjustment shall be made, and such adjustment shall be the
amount of adjustment that has the highest absolute value.

            (j) If the Trust shall take any action affecting the Common Shares,
other than action described in this Section 7, that in the opinion of the Board
of Trustees would materially


                                     - 15 -
<PAGE>


adversely affect the conversion rights of the holders of the Series A Preferred
Shares, the Conversion Price for the Series A Preferred Shares may be adjusted,
to the extent permitted by law, in such manner, if any, and at such time, as the
Board of Trustees, in its sole discretion, may determine to be equitable in the
circumstances.

            (k) The Trust will at all times reserve and keep available, free
from preemptive rights, out of the aggregate of its authorized but unissued
Common Shares, for the purpose of effecting conversion of the Series A Preferred
Shares, the full number of Common Shares deliverable upon the conversion of all
outstanding Series A Preferred Shares not theretofore converted. For purposes of
this paragraph (k), the number of Common Shares that shall be deliverable upon
the conversion of all outstanding Series A Preferred Shares shall be computed as
if at the time of computation all such outstanding shares were held by a single
holder.

The Trust covenants that any Common Shares issued upon conversion of the Series
A Preferred Shares shall be validly issued, fully paid and non-assessable.
Before taking any action that would cause an adjustment reducing the Conversion
Price below the then-par value of the Common Shares deliverable upon conversion
of the Series A Preferred Shares, the Trust shall take any trust action that, in
the opinion of its counsel, may be necessary in order that the Trust may validly
and legally issue fully paid and non-assessable Common Shares at such adjusted
Conversion Price.

The Trust shall endeavor to list the Common Shares required to be delivered upon
conversion of the Series A Preferred Shares, prior to such delivery, upon each
national securities exchange, if any, upon which the outstanding Common Shares
are listed at the time of such delivery.

            (l) The Trust shall pay any and all documentary stamp or similar
issue or transfer taxes payable in respect of the issue or delivery of Common
Shares or other securities or property on conversion of the Series A Preferred
Shares pursuant hereto; provided, however, that the Trust shall not be required
to pay any tax that may be payable in respect of any transfer involved in the
issue or delivery of any Common Shares or other securities or property in a name
other than that of the holder of the Series A Preferred Shares to be converted,
and no such issue or delivery shall be made unless and until the person
requesting such issue or delivery has paid to the Trust the amount of any such
tax or established, to the reasonable satisfaction of the Trust, that such tax
has been paid.

            (m) The Trust shall provide each holder of Series A Preferred Shares
with written notice (an "Issuance Notice") of any proposed issuance for cash of
Common Shares or securities convertible into Common Shares (other than limited
partnership interests) no later than 10 business days prior to the proposed
issuance thereof. Such Issuance Notice shall specify the purchase price, the
proposed issuance date and all other material terms of such issuance. Upon
delivery to the Trust by any such holder no more than 10 business days after
such Issuance Notice is given to such holder of a notice stating that such
holder intends to acquire a portion of


                                     - 16 -
<PAGE>


the Common Shares or convertible securities to be issued, such holder shall be
entitled, on the terms offered by the Trust to other prospective purchasers of
the Common Shares or convertible securities to be issued, to purchase up to an
amount of the securities such that, upon consummation of the proposed issuance,
the holder would hold the same percentage of the Common Shares as such holder
holds immediately prior to such issuance (in each case on an as-converted
basis). Any such notice from any such holder shall indicate the amount of Common
Shares or convertible securities it intends to purchase and shall constitute a
binding contract to acquire such Common Shares or convertible securities on the
terms set forth in the Issuance Notice delivered to such holder by the Trust.
Notwithstanding anything herein to the contrary, the Trust shall be entitled not
to proceed with the proposed issuance or to alter the terms thereof; provided
that, in the event that any material terms of the proposed issuance are altered,
(i) any notice delivered by a holder to the Trust pursuant to this paragraph (m)
of Section 7 shall be revoked automatically and (ii) such holder shall be
entitled to participate in such proposed issuance on the revised terms in
accordance with this paragraph (m) of Section 7. The provisions of this
paragraph (m) of Section 7 shall no longer apply and shall be of no further
effect after the Trust consummates a Qualifying Offering.

      SECTION 8. PERMISSIBLE DISTRIBUTIONS. In determining whether a
distribution (other than upon liquidation, dissolution or winding up), whether
by dividend, or upon redemption or other acquisition of shares or otherwise, is
permitted under Maryland law, amounts that would be needed, if the Trust were to
be dissolved at the time of the distribution, to satisfy the preferential rights
upon dissolution of holders of shares of beneficial interest of any class or
series whose preferential rights upon dissolution are superior or prior to those
receiving the distribution shall not be added to the Trust's total liabilities.

      SECTION 9. RANKING. Any class or series of shares of beneficial interest
of the Trust shall be deemed to rank:

            (a) prior to the Series A Preferred Shares, as to the payment of
dividends and as to distribution of assets upon liquidation, dissolution or
winding up, if the holders of such class or series shall be entitled to the
receipt of dividends or of amounts distributable upon liquidation, dissolution
or winding up, as the case may be, in preference or priority to the holders of
Series A Preferred Shares;

            (b) on a parity with the Series A Preferred Shares, as to the
payment of dividends and as to the distribution of assets upon liquidation,
dissolution or winding up, whether or not the dividend rates, dividend payment
dates or redemption or liquidation prices per share thereof be different from
those of the Series A Preferred Shares, if the holders of such class or series
and the Series A Preferred Shares shall be entitled to the receipt of dividends
and of amounts distributable upon liquidation, dissolution or winding up in
proportion to their respective amounts of accrued and unpaid dividends per share
or liquidation preferences, without preference or priority one over the other
("Parity Shares"); and


                                     - 17 -
<PAGE>


            (c) junior to the Series A Preferred Shares, as to the payment of
dividends or as to the distribution of assets upon liquidation, dissolution or
winding up, if such class or series shall be Common Shares or if the holders of
Series A Preferred Shares shall be entitled to receipt of dividends or of
amounts distributable upon liquidation, dissolution or winding up, as the case
may be, in preference or priority to the holders of such class or series, and
such class or series shall not in either case rank prior to the Series A
Preferred Shares.

      SECTION 10. VOTING. Except as otherwise set forth herein, the Series A
Preferred Shares shall not have any relative, participating, optional or other
special voting rights and powers, and the consent of the holders thereof shall
not be required for the taking of any trust action.

            (a) If and whenever six quarterly dividends (whether or not
consecutive) payable on the Series A Preferred Shares shall be in arrears (which
shall, with respect to any such quarterly dividend, mean that any such dividend
has not been paid in full), whether or not earned or declared, the number of
Trustees then constituting the Board of Trustees shall be increased by one and
the holders of Series A Preferred Shares, voting separately as a single class,
shall be entitled to nominate and elect the additional Trustee to serve on the
Board of Trustees. Whenever all arrearage in dividends on the Series A Preferred
Shares then outstanding shall have been paid and full dividends thereon for the
current quarterly dividend period shall have been paid or declared and set apart
for payment, then the right of the holders of the Series A Preferred Shares to
elect such additional Trustee shall cease (but subject always to the same
provision for the vesting of such voting rights in the case of any similar
future arrearages in six quarterly dividends), and the term of office of the
person elected as a Trustee by the holders of the Series A Preferred Shares
shall forthwith terminate and the number Trustees constituting the Board of
Trustees shall be reduced accordingly. At any time after such voting power shall
have been so vested in the holders of Series A Preferred Shares, the Secretary
of the Trust may, and upon the written request of any holder of Series A
Preferred Shares (addressed to the Secretary at the principal office of the
Trust) shall, call a special meeting of the holders of the Series A Preferred
Shares for the election of the additional Trustee to be elected by them as
herein provided, such call to be made by notice similar to that provided in the
Bylaws of the Trust for a special meeting of the shareholders or as required by
law. If any such special meeting required to be called as above provided shall
not be called by the Secretary within 20 days after receipt of such request,
then any holder of Series A Preferred Shares may call such meeting, upon the
notice above provided, and for that purpose shall have access to the share books
of the Trust. The Trustee elected at any such special meeting shall hold office
until the next annual meeting of the shareholders or special meeting held in
lieu thereof if such office shall not have previously terminated as above
provided. If the Trustee elected by the holders of the Series A Preferred Shares
shall leave the Board of Trustees, a successor shall be elected by the Board of
Trustees, upon the nomination of the holders of the Series A Preferred Shares,
to serve until the next annual meeting of the shareholders or special meeting
held in place thereof if such office shall not have previously terminated as
provided above.


                                     - 18 -
<PAGE>


            (b) So long as any Series A Preferred Shares are outstanding, in
addition to any other vote or consent of shareholders required by the
Declaration of the Trust, the affirmative vote of at least 66-2/3% of the votes
entitled to be cast by the holders of Series A Preferred Shares, at the time
outstanding, voting as a single class, given in person or by proxy, either in
writing without a meeting or by vote at any meeting called for the purpose,
shall be necessary for effecting or validating:

                  (i) Any amendment, alteration or repeal of any of the
provisions of the Declaration or these Articles Supplementary that materially
and adversely affects the voting powers, rights or preferences of the holders of
the Series A Preferred Shares; provided, however, that (A) the amendment of the
provisions of the Declaration so as to authorize or create or to increase the
authorized amount of, any Junior Shares or any shares of any class or series
ranking on a parity with the Series A Preferred Shares shall not be deemed to
materially adversely affect the voting powers, rights or preferences of the
holders of Series A Preferred Shares and (B) any filing with the State
Department of Assessments and Taxation of Maryland by the Trust in connection
with a merger, consolidation or sale of all or substantially all of the assets
of the Trust shall not be deemed to be an amendment, alteration or repeal of any
of the provisions of the Declaration; or

                  (ii) The authorization or creation of, or the increase in the
authorized amount of, any shares of any class or series or any security
convertible into shares of any class or series ranking prior to the Series A
Preferred Shares in the distribution of assets on any liquidation, dissolution
or winding up of the Trust or in the payment of dividends;

provided, however, that, in the case of each of subparagraphs (a) and (b), no
such vote of the holders of Series A Preferred Shares shall be required if, at
or prior to the time when such amendment, alteration or repeal is to take
effect, or when the issuance of any such prior shares or convertible security is
to be made, as the case may be, provision is made for the redemption of all
Series A Preferred Shares, as the case may be, at the time outstanding in
accordance with Section 5 hereof.

For purposes of the foregoing provisions of this Section 10, each Series A
Preferred Share shall have one (1) vote per share.

      SECTION 11. RECORD HOLDERS. The Trust may deem and treat the record holder
of any Series A Preferred Shares as the true and lawful owner thereof for all
purposes, and the Trust shall not be affected by any notice to the contrary.

      SECTION 12. RESTRICTIONS ON OWNERSHIP AND TRANSFER. The Series A Preferred
Shares constitute Preferred Shares, and Preferred Shares constitutes Shares of
the Trust. Therefore, the Series A Preferred Shares, being Shares, are governed
by and issued subject to all the limitations, terms and conditions of the
Declaration applicable to Shares generally, including but not limited to the
terms and conditions (including exceptions and


                                     - 19 -
<PAGE>


exemptions) of Article IV of the Declaration applicable to Shares. The foregoing
sentence shall not be construed to limit the applicability to the Series A
Preferred Shares of any other term or provision of the Declaration.


                                     - 20 -
<PAGE>


      IN WITNESS WHEREOF, KEYSTONE PROPERTY TRUST has caused these presents to
be signed in its name and on its behalf by its Vice President and witnessed to
by its Secretary as of October 7, 1999.

WITNESS:                                  KEYSTONE PROPERTY TRUST

/s/  Timothy A. Peterson                  By:  /s/  Stephen J. Butte
------------------------                       ---------------------
     Timothy A. Peterson,                            Stephen J. Butte,
     Secretary                                       Vice President



      The UNDERSIGNED, Vice President of KEYSTONE PROPERTY TRUST, who executed
on behalf of the Trust these Articles Supplementary of which this certificate is
made a part, hereby acknowledges in the name and on behalf of said Trust the
foregoing Articles Supplementary to be the act of said Trust and hereby
certifies that the matters and facts set forth herein with respect to the
authorization and approval thereof are true in all material respects under the
penalties of perjury.



                                          /s/  Stephen J. Butte
                                          ---------------------
                                               Stephen J. Butte,
                                               Vice President


                                     - 21 -