<Page>

                                                                     EXHIBIT 3.6

                              iSTAR FINANCIAL INC.

                             Articles Supplementary

     iStar Financial Inc., a Maryland corporation, (the "Corporation"), hereby
certifies to the State Department of Assessments and Taxation of Maryland that:

     FIRST: Under a power contained in Article V of the Charter of the
Corporation (the "Charter"), the Board by duly adopted resolutions classified
and designated 5,000 shares of authorized but unissued shares of Common Stock
(as defined in the Charter) as shares of High Performance Common Stock-Series 4,
with the following preferences, conversion and other rights, voting powers,
restrictions, limitations as to dividends and other distributions,
qualifications, and terms and conditions of redemption, which, upon any
restatement of the Charter, shall become part of Article V of the Charter, with
any necessary or appropriate renumbering or relettering of the sections or
subsections hereof.

                     HIGH PERFORMANCE COMMON STOCK- SERIES 4

1.   DESIGNATION AND NUMBER. A series of Common Stock, designated High
Performance Common Stock-Series 4 ("HP Series 4 Stock"), is hereby established.
The number of shares of HP Series 4 Stock shall be 5,000. The number of shares
of HP Series 4 Stock may be increased or decreased (but not below the number of
shares of HP Series 4 Stock then issued and outstanding) from time to time by
resolution of the Board. HP Series 4 Stock repurchased by the Corporation shall
be canceled and shall revert to authorized but unissued shares of Common Stock,
undesignated as to class or series, subject to reclassification and reissuance
by the Corporation in accordance with the Charter.

2.   RANK. The HP Series 4 Stock shall, with respect to dividend rights and
rights upon liquidation, dissolution or winding up of the Corporation, rank (a)
on a parity with the Common Stock; and (b) junior to the Corporation's 9.5%
Series A Cumulative Redeemable Preferred Stock (the "Series A Preferred Stock"),
9-3/8% Series B Cumulative Redeemable Preferred Stock (the "Series B Preferred
Stock"), 9.2% Series C Cumulative Redeemable Preferred Stock (the "Series C
Preferred Stock") and 8% Series D Cumulative Redeemable Preferred Stock (the
"Series D Preferred Stock"), and all equity securities issued by the Corporation
the terms of which specifically provide that such equity securities rank senior
to the HP Series 4 Stock.

3.   VOTING RIGHTS. Each share of HP Series 4 Stock (voting together as a single
class with all Common Stock (including any High Performance Common Stock-Series
1, High Performance Common Stock-Series 2, High Performance Common Stock-Series
3, and High Performance Common Stock-Series 5) and all Preferred Stock entitled
to vote) will be entitled to cast twenty-five one-hundredths of one vote with
respect to all matters on which the holders of Common Stock are entitled to
vote. Shares of HP Series 4 Stock shall not have cumulative voting rights.

4.   DIVIDENDS

     (a)  Each share of HP Series 4 Stock shall be entitled to receive dividends
in the same amount and at the same times as regular quarterly cash dividends are
paid on a number of shares of Common Stock equal to the Common Stock Equivalent,
as defined below. For the avoidance of doubt, shares of HP Series 4 Stock shall
not be entitled to receive dividends in respect of any dividend or other
distribution paid on the Common Stock other than regular quarterly cash
dividends.

<Page>

     (b)  Each dividend will be payable to holders of record of the HP Series 4
Stock on a date (a "Record Date") selected by the Board which is the same date
as the Record Date for the payment of the related dividend or other distribution
on the Common Stock.

     (c)  Except as otherwise provided in paragraph (d), the Common Stock
Equivalent shall be 0.01 shares of Common Stock.

     (d)  If the Cumulative Total Return of the Common Stock during the
Measurement Period exceeds the Threshold Return, then with respect to each
dividend declared after the Valuation Date, the Common Stock Equivalent shall be
deemed to equal: (1) the product of (w) 7.5% of the amount by which the
Cumulative Total Return of the Common Stock during the Measurement Period
exceeds the Threshold Return multiplied by (x) the Average Market Capitalization
of the Common Stock for the Measurement Period; divided by (2) the product of
(y) the Security Price of one share of Common Stock as of the Valuation Date and
(z) the number of shares of HP Series 4 Stock Outstanding at the close of
business, New York time, on the Valuation Date; PROVIDED, HOWEVER, that in no
event shall the Common Stock Equivalent exceed the quotient of (A) 1.0% of the
average number of shares of Common Stock outstanding on the last day of each
full calendar month during the Measurement Period, on a fully diluted basis,
divided by (B) the number of shares of HP Series 4 Stock outstanding on the
Valuation Date.

5.   RIGHTS UPON LIQUIDATION, DISSOLUTION OR WINDING UP. In the event of any
liquidation, dissolution or winding up of the Company, whether voluntary or
involuntary, each share of HP Series 4 Stock shall be entitled, on the same
basis as the Common Stock Equivalent and any other class of stock hereafter
classified or reclassified that does not have a preference on distributions in
the liquidation, dissolution or winding up of the Company, to share ratably in
the net assets of the Company remaining, after payment or provision for payment
of the debts and other liabilities of the Company and the amount to which the
holders of any class of stock of the Company that has a preference on
distributions in the liquidation, dissolution or winding up of the Company shall
be entitled. The consolidation or merger of the Corporation with or into any
other corporation, trust or entity or of any other corporation with or into the
Corporation, or the sale, lease or conveyance of all or substantially all of the
property or business of the Corporation, shall not be deemed to constitute a
liquidation, dissolution or winding up of the Corporation.

6.   REDEMPTION. The HP Series 4 Stock is not redeemable, except in the
following instances:

     (a)  In order to ensure that the Corporation remains a qualified real
estate investment trust for Federal income tax purposes, the HP Series 4 Stock
will be subject to the provisions of Article IX of the Charter. Without limiting
the generality of the foregoing, pursuant to Article IX, HP Series 4 Stock,
together with other equity stock of the Corporation, owned by a stockholder in
excess of the Ownership Limit will automatically be transferred to a Charitable
Trust for the benefit of a Charitable Beneficiary and the Corporation will have
the right to purchase such transferred shares from the Charitable Trust.

     (b)  The Corporation shall have the right, but not the obligation, to
redeem shares of HP Series 4 Stock held by iStar HPU 2005, L.L.C. (the "LLC")
upon receipt of a written notice (an "LLC Redemption Notice") from the managing
member of the LLC of a proposed redemption by the LLC of units of interest in
the LLC pursuant to the LLC's operating agreement. The LLC Redemption Notice
shall specify the number of units of LLC interest to be redeemed, the redemption
price and the date on which the redemption shall take place. The number of
shares of HP Series 4 Stock that may be redeemed by the Corporation and the
redemption price to be paid by the Corporation shall be the same as the number
of units of LLC interest proposed to be redeemed and the redemption price to be
paid for such units, in each case as set forth in the LLC Redemption Notice. In
order for the Corporation to exercise its right of redemption hereunder, the
Corporation shall advise the LLC in writing, as promptly as practicable

                                        2
<Page>

and in any event within 10 business days after receipt of the LLC Redemption
Notice, of its intent to redeem HP Series 4 Stock in response to the LLC
Redemption Notice and shall specify a date for such redemption, which date shall
be no later than 10:00 a.m., New York time, on the redemption date specified in
the LLC Redemption Notice.

     (c)  Notice of redemption of HP Series 4 Stock having been given in
accordance with the previous paragraph, on or before the redemption date, the
LLC shall surrender the certificates representing the shares of HP Series 4
Stock to be redeemed to the Corporation. Promptly after the certificates
representing HP Series 4 Stock are surrendered to the Corporation, the
Corporation will deliver to the LLC the consideration for such shares.

     (d)  The Corporation shall redeem for cash all outstanding shares of HP
Series 4 Stock at a redemption price per share equal to the Security Price of
the Common Stock as of the first date on which the Corporation is no longer
treated as a real estate investment trust for U.S. federal income tax purposes.
Such redemption shall take place no later than 60 days after the first date on
which the Corporation is no longer treated as a real estate investment trust for
U.S. federal income tax purposes.

     (e)  At the close of business on the redemption date for shares of HP
Series 4 Stock, the holders of the shares called for redemption will cease to be
stockholders with respect to those shares, will have no interest in or claims
against the Corporation by virtue of the shares and will have no voting or other
rights with respect to the shares (except the right to receive the redemption
price, and except the right to receive dividends or distributions payable
thereafter to the holder of the HP Series 4 Stock as of a Record Date preceding
such redemption date) and, from and after the close of business on the
redemption date the shares of HP Series 4 Stock to be redeemed or exchanged will
no longer be deemed outstanding.

     (f)  If a Record Date occurs prior to a redemption date for shares of HP
Series 4 Stock but the corresponding dividend payment date occurs after the
redemption date, the dividend payable on such dividend payment date will be
payable on the dividend payment date to the holder of record of the shares of HP
Series 4 Stock on the Record Date notwithstanding the redemption of the shares
of HP Series 4 Stock on the redemption date.

7.   CONVERSION. If the Corporation consolidates or merges with or into any
person, or sells, assigns, transfers, leases or otherwise disposes of all or
substantially all of its consolidated assets to another person, in a single
transaction or a series of related transactions in which (1) the Corporation is
not the surviving or continuing person and (2) the common stock of the
Corporation is converted or exchanged into cash or other property or securities
of the surviving or continuing person (a "Change of Control"), then at the
effective time of the completion of such Change of Control transaction, each
share of HP Series 4 Common Stock shall automatically be converted into the same
type and amount of consideration as a number of shares of common stock equal to
the Common Stock Equivalent in effect at the effective time of the completion of
the transaction.

8.   DEFINITIONS.  As used herein, the following terms shall have the following
meanings:

     "AVERAGE MARKET CAPITALIZATION" means the weighted average of the common
equity market capitalization of the Corporation for each calendar month of the
Measurement Period, as calculated by multiplying the number of basic shares of
Common Stock outstanding on the last day of each calendar month by the average
daily closing price of the Common Stock for each such month.

     "CHANGE OF CONTROL" means, a transaction of the type contemplated by
paragraph 7 "Conversion" of these Articles.

                                        3
<Page>

     "CHANGE OF CONTROL PRICE" means, if the Common Stock is publicly traded on
a U.S. national securities exchange or automated quotation system prior to the
occurrence of a Change of Control, then the closing price of the Common Stock at
the end of regular trading on the last trading day prior to the occurrence of
the Change of Control, and otherwise shall mean the fair market value of the
Common Stock on the day prior to the occurrence of the Change of Control as
determined by the Board.

     "CUMULATIVE TOTAL RETURN" means, for any security and for any period, the
cumulative total return for such security over such period, as measured by (1)
the sum of (a) the cumulative amount of dividends paid in respect of such
security for such period (assuming that all cash dividends are reinvested in
such security as of the payment date for such dividend based on the Security
Price as of the dividend payment date), and (b) an amount equal to (x) the
Change of Control Price or, if no Change of Control has occurred, the Security
Price as of the last day of the Measurement Period, minus (y) the closing price
of the security, as reported by the principal stock exchange or automated
quotation system on which the security is then traded, on the last trading day
prior to the first day of the Measurement Period, divided by (2) the closing
price of the security, as reported by the principal stock exchange or automated
quotation system on which the security is then traded, on the last trading day
prior to the first day of the Measurement Period; provided, however, that if the
foregoing calculation results in a negative number, the "Cumulative Total
Return" shall be equal to zero.

     "INDEX RETURN" means the Cumulative Total Return, expressed as a
percentage, achieved by the Peer Group Index during the Measurement Period.

     "SECURITY PRICE" means, for any security, the average of the closing prices
for such security on the principal securities exchange or automated quotation
system on which the security is traded or listed for the 20 trading days ended
on the trading date immediately preceding the date as of which the Security
Price is being determined; provided, however, that if the security is not
publicly-traded, then the Security Price shall be equal to the fair market value
of the security as determined by the Board.

     "MEASUREMENT PERIOD" means the period from and including January 1, 2005 to
and including the Valuation Date.

     "PEER GROUP INDEX" means, initially, a combination of The Morgan Stanley
Dean Witter REIT Index and the Russell 1000 Financial Index, with each such
index being accorded equal weighting. The Board may select one or more different
indices to serve as the Peer Group Index from time to time if the Board
determines that the applicable indices no longer serve as an appropriate
comparison for the Company, or if they are not maintained throughout the
Measurement Period or for any other reason the Board may determine.

     "THRESHOLD RETURN" means the greater of (1) 10% and (2) the Index Return.

     "VALUATION DATE" means the earlier of (1) December 31, 2005, (2) the date
of the occurrence of a Change of Control of the Company and (3) the date of any
liquidation, dissolution or winding up of the Company.

     SECOND: The shares of High Performance Common Stock-Series 4 have been
classified and designated by the Board of Directors under the authority
contained in the Charter.

     THIRD: These Articles Supplementary have been approved by the Board of
Directors in the manner and by the vote required by law.

                                        4
<Page>

     FOURTH: The undersigned Chairman and Chief Executive Officer of the
Corporation acknowledges these Articles Supplementary to be the corporate act of
the Corporation and, as to all matters or facts required to be verified under
oath, the undersigned Chairman and Chief Executive Officer acknowledges that, to
the best of his knowledge, information and belief, these matters and facts are
true in all material respects and that this statement is made under the
penalties for perjury.

                            [SIGNATURE PAGE FOLLOWS]

                                        5
<Page>

IN WITNESS WHEREOF, the Corporation has caused these Articles Supplementary to
be signed in its name and on its behalf by its Chairman and attested to by its
Secretary on this 22 day of January, 2003.

ATTEST:                                   iSTAR FINANCIAL INC.


By:  /s/ Catherine D. Rice                By: /s/ Jay Sugarman            (SEAL)
   ---------------------------------         -----------------------------
    Name: Catherine D. Rice                  Name: Jay S. Sugarman
    Title: Chief Financial Officer           Title: Chairman and CEO
            and Secretary

                                        6