Exhibit 4.1 

WARRANT TO PURCHASE COMMON
STOCK 

THE SECURITIES REPRESENTED BY THIS
INSTRUMENT HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS
AMENDED, OR THE SECURITIES LAWS OF ANY STATE AND MAY NOT BE TRANSFERRED, SOLD OR
OTHERWISE DISPOSED OF EXCEPT WHILE A REGISTRATION STATEMENT RELATING THERETO IS
IN EFFECT UNDER SUCH ACT AND APPLICABLE STATE SECURITIES LAWS OR PURSUANT TO AN
EXEMPTION FROM REGISTRATION UNDER SUCH ACT OR SUCH LAWS. THIS INSTRUMENT IS
ISSUED SUBJECT TO THE RESTRICTIONS ON TRANSFER AND OTHER PROVISIONS OF A
SECURITIES PURCHASE AGREEMENT BETWEEN THE ISSUER
OF THESE SECURITIES AND THE INVESTOR REFERRED TO THEREIN, A COPY OF WHICH IS ON
FILE WITH THE ISSUER. THE SECURITIES REPRESENTED BY THIS INSTRUMENT MAY NOT BE
SOLD OR OTHERWISE TRANSFERRED EXCEPT IN COMPLIANCE WITH SAID AGREEMENT. ANY SALE
OR OTHER TRANSFER NOT IN COMPLIANCE WITH SAID AGREEMENT WILL BE VOID.

WARRANT 
to purchase
324,074
Shares of Common Stock
of Enterprise Financial
Services Corp

Issue Date: December 19,
2008 

     1.
Definitions. Unless the context otherwise requires, when used herein the following
terms shall have the meanings indicated.


     “Affiliate” has the meaning ascribed to
it in the Purchase Agreement. 

     “Appraisal Procedure” means a procedure whereby two independent appraisers, one
chosen by the Company and one by the Original Warrantholder, shall mutually
agree upon the determinations then the subject of appraisal. Each party shall
deliver a notice to the other appointing its appraiser within 15 days after the
Appraisal Procedure is invoked. If within 30 days after appointment of the two
appraisers they are unable to agree upon the amount in question, a third
independent appraiser shall be chosen within 10 days thereafter by the mutual
consent of such first two appraisers. The decision of the third appraiser so
appointed and chosen shall be given within 30 days after the selection of such
third appraiser. If three appraisers shall be appointed and the determination of
one appraiser is disparate from the middle determination by more than twice the
amount by which the other determination is disparate from the middle
determination, then the determination of such appraiser shall be excluded, the
remaining two determinations shall be averaged and such average shall be binding
and conclusive upon the Company and the Original Warrantholder; otherwise, the
average of all three determinations shall be binding upon the Company and the
Original Warrantholder. The costs of conducting any Appraisal Procedure shall be
borne by the Company.




     “Board of Directors” means the board of directors of the Company, including any
duly authorized committee thereof. 

     “Business Combination” means a merger, consolidation, statutory share exchange or
similar transaction that requires the approval of the Company’s
stockholders. 

     “business day” means any day except Saturday, Sunday and any day on which
banking institutions in the State of New York generally are authorized or
required by law or other governmental actions to close. 

     “Capital Stock” means (A) with respect to any Person that is a corporation
or company, any and all shares, interests, participations or other equivalents
(however designated) of capital or capital stock of such Person and (B) with
respect to any Person that is not a corporation or company, any and all
partnership or other equity interests of such Person. 

     “Charter” means, with respect to any Person, its certificate or articles of
incorporation, articles of association, or similar organizational
document. 

     “Common Stock” has the meaning ascribed
to it in the Purchase Agreement. 

     “Company” means the Person whose name, corporate or other organizational form and
jurisdiction of organization is set forth in Item 1 of Schedule A
hereto. 

     “conversion” has the meaning set forth
in Section 13(B). 

     “convertible securities” has the
meaning set forth in Section 13(B). 

     “CPP” has the meaning ascribed to it in
the Purchase Agreement. 

     “Exchange Act” means the Securities Exchange Act of 1934, as amended, or
any successor statute, and the rules and regulations promulgated
thereunder. 

     “Exercise Price” means the amount set
forth in Item 2 of Schedule A hereto. 

     “Expiration Time” has the meaning set forth in Section 3. 

     “Fair Market Value” means, with respect to any security or other property, the
fair market value of such security or other property as determined by the Board
of Directors, acting in good faith or, with respect to Section 14, as determined
by the Original Warrantholder acting in good faith. For so long as the Original
Warrantholder holds this Warrant or any portion thereof, it may object in
writing to the Board of Director’s calculation of fair market value within 10
days of receipt of written notice thereof. If the Original Warrantholder and the
Company are unable to agree on fair market value during the 10-day period
following the delivery of the Original Warrantholder’s objection, the Appraisal
Procedure may be invoked by either party to determine Fair Market Value by
delivering written notification thereof not later than the 30th day after delivery of
the Original Warrantholder’s objection.

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     “Governmental Entities” has the meaning
ascribed to it in the Purchase Agreement.


     “Initial Number” has the meaning set
forth in Section 13(B). 

     “Issue Date” means the date set forth in Item 3 of Schedule A
hereto. 

     “Market Price” means, with respect to a particular security, on any given
day, the last reported sale price regular way or, in case no such reported sale
takes place on such day, the average of the last closing bid and ask prices
regular way, in either case on the principal national securities exchange on
which the applicable securities are listed or admitted to trading, or if not
listed or admitted to trading on any national securities exchange, the average
of the closing bid and ask prices as furnished by two members of the Financial
Industry Regulatory Authority, Inc. selected from time to time by the Company
for that purpose. “Market Price” shall be determined without reference to after
hours or extended hours trading. If such security is not listed and traded in a
manner that the quotations referred to above are available for the period
required hereunder, the Market Price per share of Common Stock shall be deemed
to be (i) in the event that any portion of the Warrant is held by the Original
Warrantholder, the fair market value per share of such security as determined in
good faith by the Original Warrantholder or (ii) in all other circumstances, the
fair market value per share of such security as determined in good faith by the
Board of Directors in reliance on an opinion of a nationally recognized
independent investment banking corporation retained by the Company for this
purpose and certified in a resolution to the Warrantholder. For the purposes of
determining the Market Price of the Common Stock on the "trading day" preceding,
on or following the occurrence of an event, (i) that trading day shall be deemed
to commence immediately after the regular scheduled closing time of trading on
the New York Stock Exchange or, if trading is closed at an earlier time, such
earlier time and (ii) that trading day shall end at the next regular scheduled
closing time, or if trading is closed at an earlier time, such earlier time (for
the avoidance of doubt, and as an example, if the Market Price is to be
determined as of the last trading day preceding a specified event and the
closing time of trading on a particular day is 4:00 p.m. and the specified event
occurs at 5:00 p.m. on that day, the Market Price would be determined by
reference to such 4:00 p.m. closing price).


     “Ordinary Cash
Dividends” means a regular quarterly cash
dividend on shares of Common Stock out of surplus or net profits legally
available therefor (determined in accordance with generally accepted accounting
principles in effect from time to time), provided that Ordinary Cash Dividends
shall not include any cash dividends paid subsequent to the Issue Date to the
extent the aggregate per share dividends paid on the outstanding Common Stock in
any quarter exceed the amount set forth in Item 4 of Schedule A hereto, as
adjusted for any stock split, stock dividend, reverse stock split,
reclassification or similar transaction.


     “Original Warrantholder” means the United States Department of the Treasury. Any
actions specified to be taken by the Original Warrantholder hereunder may only
be taken by such Person and not by any other Warrantholder. 

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     “Permitted Transactions” has the
meaning set forth in Section 13(B). 

     “Person” has the meaning given to it in Section 3(a)(9) of the Exchange Act and
as used in Sections 13(d)(3) and 14(d)(2) of the Exchange Act. 

     “Per Share Fair Market
Value” has the meaning set forth in Section
13(C). 

     “Preferred
Shares” means the perpetual preferred stock
issued to the Original Warrantholder on the Issue Date pursuant to the Purchase
Agreement. 

     “Pro Rata Repurchases” means any purchase of shares of Common Stock by the Company
or any Affiliate thereof pursuant to (A) any tender offer or exchange offer
subject to Section 13(e) or 14(e) of the Exchange Act or Regulation 14E
promulgated thereunder or (B) any other offer available to substantially all
holders of Common Stock, in the case of both (A) or (B), whether for cash,
shares of Capital Stock of the Company, other securities of the Company,
evidences of indebtedness of the Company or any other Person or any other
property (including, without limitation, shares of Capital Stock, other
securities or evidences of indebtedness of a subsidiary), or any combination
thereof, effected while this Warrant is outstanding. The “Effective Date” of a Pro
Rata Repurchase shall mean the date of acceptance of shares for purchase or
exchange by the Company under any tender or exchange offer which is a Pro Rata
Repurchase or the date of purchase with respect to any Pro Rata Repurchase that
is not a tender or exchange offer. 

     “Purchase Agreement” means the Securities Purchase Agreement – Standard Terms
incorporated into the Letter Agreement, dated as of the date set forth in Item 5
of Schedule A hereto, as amended from time to time, between the Company and the
United States Department of the Treasury (the “Letter Agreement”), including all
annexes and schedules thereto. 

     “Qualified Equity
Offering” has the meaning ascribed to it in
the Purchase Agreement. 

     “Regulatory Approvals” with
respect to the Warrantholder, means, to the extent applicable and required to
permit the Warrantholder to exercise this Warrant for shares of Common Stock and
to own such Common Stock without the Warrantholder being in violation of
applicable law, rule or regulation, the receipt of any necessary approvals and
authorizations of, filings and registrations with, notifications to, or
expiration or termination of any applicable waiting period under, the
Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended, and the rules
and regulations thereunder. 

     “SEC” means the U.S. Securities and
Exchange Commission. 

     “Securities Act” means the Securities Act of 1933, as amended, or any
successor statute, and the rules and regulations promulgated
thereunder. 

     “Shares” has the meaning set forth in
Section 2. 

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     “trading
day” means (A) if the shares of Common Stock
are not traded on any national or regional securities exchange or association or
over-the-counter market, a business day or (B) if the shares of Common Stock are
traded on any national or regional securities exchange or association or over-the-counter market, a business day on which
such relevant exchange or quotation system is scheduled to be open for business
and on which the shares of Common Stock (i) are not suspended from trading on
any national or regional securities exchange or association or over-the-counter
market for any period or periods aggregating one half hour or longer; and (ii)
have traded at least once on the national or regional securities exchange or
association or over-the-counter market that is the primary market for the
trading of the shares of Common Stock.

     “U.S. GAAP” means United States
generally accepted accounting principles. 

     “Warrantholder” has the meaning set
forth in Section 2. 

     “Warrant” means this Warrant, issued
pursuant to the Purchase Agreement. 

     2. Number
of Shares; Exercise Price. This certifies
that, for value received, the United States Department of the Treasury or its
permitted assigns (the “Warrantholder”) is entitled, upon the
terms and subject to the conditions hereinafter set forth, to acquire from the
Company, in whole or in part, after the receipt of all applicable Regulatory
Approvals, if any, up to an aggregate of the number of fully paid and
nonassessable shares of Common Stock set forth in Item 6 of Schedule A hereto,
at a purchase price per share of Common Stock equal to the Exercise Price. The
number of shares of Common Stock (the “Shares”) and the Exercise Price are
subject to adjustment as provided herein, and all references to “Common Stock,”
“Shares” and “Exercise Price” herein shall be deemed to include any such
adjustment or series of adjustments. 

     3. Exercise of Warrant; Term. Subject to
Section 2, to the extent permitted by applicable laws and regulations, the right
to purchase the Shares represented by this Warrant is exercisable, in whole or
in part by the Warrantholder, at any time or from time to time after the
execution and delivery of this Warrant by the Company on the date hereof, but in
no event later than 5:00 p.m., New York City time on the tenth anniversary of
the Issue Date (the “Expiration
Time”), by (A) the surrender of this Warrant
and Notice of Exercise annexed hereto, duly completed and executed on behalf of
the Warrantholder, at the principal executive office of the Company located at
the address set forth in Item 7 of Schedule A hereto (or such other office or
agency of the Company in the United States as it may designate by notice in
writing to the Warrantholder at the address of the Warrantholder appearing on
the books of the Company), and (B) payment of the Exercise Price for the Shares
thereby purchased:

          (i) by
having the Company withhold, from the shares of Common Stock that would
otherwise be delivered to the Warrantholder upon such exercise, shares of Common
stock issuable upon exercise of the Warrant equal in value to the aggregate
Exercise Price as to which this Warrant is so exercised based on the Market
Price of the Common Stock on the trading day on which this Warrant is exercised
and the Notice of Exercise is delivered to the Company pursuant to this Section
3, or 

          (ii) with the consent of both the Company and the
Warrantholder, by tendering in cash, by certified or cashier’s check payable to
the order of the Company, or by wire transfer of immediately available funds to
an account designated by the Company.

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          If the
Warrantholder does not exercise this Warrant in its entirety, the Warrantholder will be entitled to receive from the Company
within a reasonable time, and in any event not exceeding three business days, a
new warrant in substantially identical form for the purchase of that number of
Shares equal to the difference between the number of Shares subject to this
Warrant and the number of Shares as to which this Warrant is so exercised.
Notwithstanding anything in this Warrant to the
contrary, the Warrantholder hereby acknowledges and agrees that its exercise of
this Warrant for Shares is subject to the condition that the Warrantholder will
have first received any applicable Regulatory Approvals.

     4. Issuance of Shares; Authorization; Listing. Certificates for Shares issued upon exercise of this Warrant will be
issued in such name or names as the Warrantholder may designate and will be
delivered to such named Person or Persons within a reasonable time, not to
exceed three business days after the date on which this Warrant has been duly
exercised in accordance with the terms of this Warrant. The Company hereby
represents and warrants that any Shares issued upon the exercise of this Warrant
in accordance with the provisions of Section 3 will be duly and validly
authorized and issued, fully paid and nonassessable and free from all taxes,
liens and charges (other than liens or charges created by the Warrantholder,
income and franchise taxes incurred in connection with the exercise of the
Warrant or taxes in respect of any transfer occurring contemporaneously
therewith). The Company agrees that the Shares so issued will be deemed to have
been issued to the Warrantholder as of the close of business on the date on
which this Warrant and payment of the Exercise Price are delivered to the
Company in accordance with the terms of this Warrant, notwithstanding that the
stock transfer books of the Company may then be closed or certificates
representing such Shares may not be actually delivered on such date. The Company
will at all times reserve and keep available, out of its authorized but unissued
Common Stock, solely for the purpose of providing for the exercise of this
Warrant, the aggregate number of shares of Common Stock then issuable upon
exercise of this Warrant at any time. The Company will (A) procure, at its sole
expense, the listing of the Shares issuable upon exercise of this Warrant at any
time, subject to issuance or notice of issuance, on all principal stock
exchanges on which the Common Stock is then listed or traded and (B) maintain
such listings of such Shares at all times after issuance. The Company will use
reasonable best efforts to ensure that the Shares may be issued without
violation of any applicable law or regulation or of any requirement of any
securities exchange on which the Shares are listed or traded. 

     5. No
Fractional Shares or Scrip. No fractional
Shares or scrip representing fractional Shares shall be issued upon any exercise
of this Warrant. In lieu of any fractional Share to which the Warrantholder
would otherwise be entitled, the Warrantholder shall be entitled to receive a
cash payment equal to the Market Price of the Common Stock on the last trading
day preceding the date of exercise less the pro-rated Exercise Price for such
fractional share. 

     6. No
Rights as Stockholders; Transfer Books. This
Warrant does not entitle the Warrantholder to any voting rights or other rights
as a stockholder of the Company prior to the date of exercise hereof. The
Company will at no time close its transfer books against transfer of this
Warrant in any manner which interferes with the timely exercise of this Warrant.


6 




     7. Charges, Taxes and Expenses. Issuance
of certificates for Shares to the Warrantholder upon the exercise of this
Warrant shall be made without charge to the Warrantholder for any issue or transfer tax or other incidental expense
in respect of the issuance of such certificates, all of which taxes and expenses
shall be paid by the Company. 

     8.
Transfer/Assignment. 

     (A) Subject
to compliance with clause (B) of this Section 8, this Warrant and all rights
hereunder are transferable, in whole or in part, upon the books of the Company
by the registered holder hereof in person or by duly authorized attorney, and a
new warrant shall be made and delivered by the Company, of the same tenor and
date as this Warrant but registered in the name of one or more transferees, upon
surrender of this Warrant, duly endorsed, to the office or agency of the Company
described in Section 3. All expenses (other than stock transfer taxes) and other
charges payable in connection with the preparation, execution and delivery of
the new warrants pursuant to this Section 8 shall be paid by the Company.


     (B) The
transfer of the Warrant and the Shares issued upon exercise of the Warrant are
subject to the restrictions set forth in Section 4.4 of the Purchase Agreement.
If and for so long as required by the Purchase Agreement, this Warrant shall
contain the legends as set forth in Sections 4.2(a) and 4.2(b) of the Purchase
Agreement. 

     9. Exchange and Registry of Warrant. This
Warrant is exchangeable, upon the surrender hereof by the Warrantholder to the
Company, for a new warrant or warrants of like tenor and representing the right
to purchase the same aggregate number of Shares. The Company shall maintain a
registry showing the name and address of the Warrantholder as the registered
holder of this Warrant. This Warrant may be surrendered for exchange or exercise
in accordance with its terms, at the office of the Company, and the Company
shall be entitled to rely in all respects, prior to written notice to the
contrary, upon such registry. 

     10. Loss,
Theft, Destruction or Mutilation of Warrant.
Upon receipt by the Company of evidence reasonably satisfactory to it of the
loss, theft, destruction or mutilation of this Warrant, and in the case of any
such loss, theft or destruction, upon receipt of a bond, indemnity or security
reasonably satisfactory to the Company, or, in the case of any such mutilation,
upon surrender and cancellation of this Warrant, the Company shall make and
deliver, in lieu of such lost, stolen, destroyed or mutilated Warrant, a new
Warrant of like tenor and representing the right to purchase the same aggregate
number of Shares as provided for in such lost, stolen, destroyed or mutilated
Warrant. 

     11. Saturdays, Sundays, Holidays, etc. If
the last or appointed day for the taking of any action or the expiration of any
right required or granted herein shall not be a business day, then such action
may be taken or such right may be exercised on the next succeeding day that is a
business day. 

7 




     12. Rule 144 Information. The Company
covenants that it will use its reasonable best efforts to timely file all
reports and other documents required to be filed by it under the Securities Act
and the Exchange Act and the rules and regulations promulgated by the SEC
thereunder (or, if the Company is not required to file such reports, it will,
upon the request of any Warrantholder, make publicly available such
information as necessary to permit sales pursuant to Rule 144 under the
Securities Act), and it will use reasonable best efforts to take such further
action as any Warrantholder may reasonably request, in each case to the extent
required from time to time to enable such holder to, if permitted by the terms
of this Warrant and the Purchase Agreement, sell this Warrant without
registration under the Securities Act within the limitation of the exemptions
provided by (A) Rule 144 under the Securities Act, as such rule may be amended
from time to time, or (B) any successor rule or regulation hereafter adopted by
the SEC. Upon the written request of any Warrantholder, the Company will deliver
to such Warrantholder a written statement that it has complied with such
requirements. 

     13.
Adjustments and Other Rights. The Exercise Price and the number of Shares issuable upon
exercise of this Warrant shall be subject to adjustment from time to time as
follows; provided, that if more than one subsection of this Section 13 is applicable to a
single event, the subsection shall be applied that produces the largest
adjustment and no single event shall cause an adjustment under more than one
subsection of this Section 13 so as to result in duplication: 

     (A)
Stock Splits, Subdivisions, Reclassifications
or Combinations. If the Company shall (i)
declare and pay a dividend or make a distribution on its Common Stock in shares
of Common Stock, (ii) subdivide or reclassify the outstanding shares of Common
Stock into a greater number of shares, or (iii) combine or reclassify the
outstanding shares of Common Stock into a smaller number of shares, the number
of Shares issuable upon exercise of this Warrant at the time of the record date
for such dividend or distribution or the effective date of such subdivision,
combination or reclassification shall be proportionately adjusted so that the
Warrantholder after such date shall be entitled to purchase the number of shares
of Common Stock which such holder would have owned or been entitled to receive
in respect of the shares of Common Stock subject to this Warrant after such date
had this Warrant been exercised immediately prior to such date. In such event,
the Exercise Price in effect at the time of the record date for such dividend or
distribution or the effective date of such subdivision, combination or
reclassification shall be adjusted to the number obtained by dividing (x) the
product of (1) the number of Shares issuable upon the exercise of this Warrant
before such adjustment and (2) the Exercise Price in effect immediately prior to
the record or effective date, as the case may be, for the dividend,
distribution, subdivision, combination or reclassification giving rise to this
adjustment by (y) the new number of Shares issuable upon exercise of the Warrant
determined pursuant to the immediately preceding sentence. 

     (B) Certain Issuances of Common Shares or Convertible
Securities. Until the earlier of (i) the date
on which the Original Warrantholder no longer holds this Warrant or any portion
thereof and (ii) the third anniversary of the Issue Date, if the Company shall
issue shares of Common Stock (or rights or warrants or other securities
exercisable or convertible into or exchangeable (collectively, a
“conversion”) for shares of Common Stock) (collectively, “convertible securities”) (other than
in Permitted Transactions (as defined below) or a transaction to which
subsection (A) of this Section 13 is applicable) without consideration or at a
consideration per share (or having a conversion price per share) that is less
than 90% of the Market Price on the last trading day preceding the date of the
agreement on pricing such shares (or such convertible securities) then, in such
event: 

8 




(A) the
number of Shares issuable upon the exercise of this Warrant immediately prior to
the date of the agreement on pricing of such shares (or of such convertible
securities) (the “Initial Number”) shall be increased to the number
obtained by multiplying the Initial Number by a fraction (A) the numerator of
which shall be the sum of (x) the number of shares of Common Stock of the
Company outstanding on such date and (y) the number of additional shares of
Common Stock issued (or into which convertible securities may be exercised or
convert) and (B) the denominator of which shall be the sum of (I) the number of
shares of Common Stock outstanding on such date and (II) the number of shares of
Common Stock which the aggregate consideration receivable by the Company for the
total number of shares of Common Stock so issued (or into which convertible
securities may be exercised or convert) would purchase at the Market Price on
the last trading day preceding the date of the agreement on pricing such shares
(or such convertible securities); and 

(B) the
Exercise Price payable upon exercise of the Warrant shall be adjusted by
multiplying such Exercise Price in effect immediately prior to the date of the
agreement on pricing of such shares (or of such convertible securities) by a
fraction, the numerator of which shall be the number of shares of Common Stock
issuable upon exercise of this Warrant prior to such date and the denominator of
which shall be the number of shares of Common Stock issuable upon exercise of
this Warrant immediately after the adjustment described in clause (A) above.


     For
purposes of the foregoing, the aggregate consideration receivable by the Company
in connection with the issuance of such shares of Common Stock or convertible
securities shall be deemed to be equal to the sum of the net offering price
(including the Fair Market Value of any non-cash consideration and after
deduction of any related expenses payable to third parties) of all such
securities plus the minimum aggregate amount, if any, payable upon exercise or
conversion of any such convertible securities into shares of Common Stock; and
“Permitted Transactions” shall mean issuances (i) as consideration for or to fund the
acquisition of businesses and/or related assets, (ii) in connection with
employee benefit plans and compensation related arrangements in the ordinary
course and consistent with past practice approved by the Board of Directors,
(iii) in connection with a public or broadly marketed offering and sale of
Common Stock or convertible securities for cash conducted by the Company or its
affiliates pursuant to registration under the Securities Act or Rule 144A
thereunder on a basis consistent with capital raising transactions by comparable
financial institutions and (iv) in connection with the exercise of preemptive
rights on terms existing as of the Issue Date. Any adjustment made pursuant to
this Section 13(B) shall become effective immediately upon the date of such
issuance. 

     (C)
Other Distributions. In case the Company shall fix a record date for the making of a
distribution to all holders of shares of its Common Stock of securities,
evidences of indebtedness, assets, cash, rights or warrants (excluding Ordinary
Cash Dividends, dividends of its Common Stock and other dividends or
distributions referred to in Section 13(A)), in each such case, the Exercise
Price in effect prior to such record date shall be reduced immediately
thereafter to the price determined by multiplying the Exercise Price in effect
immediately prior to the reduction by the quotient of (x) the Market Price of
the Common Stock on the last trading day preceding the first date on which the
Common Stock trades regular way on the principal national securities exchange on
which the Common Stock is listed or admitted to trading without the right to
receive such distribution, minus the amount of cash and/or the Fair Market Value
of the securities, evidences of indebtedness, assets, rights or warrants to be
so distributed in respect of one share of Common Stock (such amount and/or Fair
Market Value, the “Per Share Fair Market
Value”) divided by (y) such Market Price on
such date specified in clause (x); such adjustment shall be made successively
whenever such a record date is fixed.  

9 




In such event, the number of Shares
issuable upon the exercise of this Warrant shall be increased to the number
obtained by dividing (x) the product of (1) the number of Shares issuable upon
the exercise of this Warrant before such adjustment, and (2) the Exercise Price
in effect immediately prior to the distribution giving rise to this adjustment
by (y) the new Exercise Price determined in accordance with the immediately
preceding sentence. In the case of adjustment for a cash dividend that is, or is
coincident with, a regular quarterly cash dividend, the Per Share Fair Market
Value would be reduced by the per share amount of the portion of the cash
dividend that would constitute an Ordinary Cash Dividend. In the event that such
distribution is not so made, the Exercise Price and the number of Shares
issuable upon exercise of this Warrant then in effect shall be readjusted,
effective as of the date when the Board of Directors determines not to
distribute such shares, evidences of indebtedness, assets, rights, cash or
warrants, as the case may be, to the Exercise Price that would then be in effect
and the number of Shares that would then be issuable upon exercise of this
Warrant if such record date had not been fixed.


     (D)
Certain Repurchases of Common
Stock. In case the Company effects a Pro Rata
Repurchase of Common Stock, then the Exercise Price shall be reduced to the
price determined by multiplying the Exercise Price in effect immediately prior
to the Effective Date of such Pro Rata Repurchase by a fraction of which the
numerator shall be (i) the product of (x) the number of shares of Common Stock
outstanding immediately before such Pro Rata Repurchase and (y) the Market Price
of a share of Common Stock on the trading day immediately preceding the first
public announcement by the Company or any of its Affiliates of the intent to
effect such Pro Rata Repurchase, minus (ii) the aggregate purchase price of the
Pro Rata Repurchase, and of which the denominator shall be the product of (i)
the number of shares of Common Stock outstanding immediately prior to such Pro
Rata Repurchase minus the number of shares of Common Stock so repurchased and
(ii) the Market Price per share of Common Stock on the trading day immediately
preceding the first public announcement by the Company or any of its Affiliates
of the intent to effect such Pro Rata Repurchase. In such event, the number of
shares of Common Stock issuable upon the exercise of this Warrant shall be
increased to the number obtained by dividing (x) the product of (1) the number
of Shares issuable upon the exercise of this Warrant before such adjustment, and
(2) the Exercise Price in effect immediately prior to the Pro Rata Repurchase
giving rise to this adjustment by (y) the new Exercise Price determined in
accordance with the immediately preceding sentence. For the avoidance of doubt,
no increase to the Exercise Price or decrease in the number of Shares issuable
upon exercise of this Warrant shall be made pursuant to this Section
13(D). 

10 




     (E)
Business Combinations. In case of any Business Combination or reclassification of
Common Stock (other than a reclassification of Common Stock referred to in
Section 13(A)), the Warrantholder’s right to receive Shares upon exercise of
this Warrant shall be converted into the right to exercise this Warrant to
acquire the number of shares of stock or other securities or property (including
cash) which the Common Stock issuable (at the time of such Business Combination
or reclassification) upon exercise of this Warrant immediately prior to such
Business Combination or reclassification would have been entitled to receive
upon consummation of such Business Combination or reclassification; and in any
such case, if necessary, the provisions set forth herein with respect to the
rights and interests thereafter of the Warrantholder shall be appropriately
adjusted so as to be applicable, as nearly as may reasonably be, to the
Warrantholder’s right to exercise this Warrant in exchange for any shares of
stock or other securities or property pursuant to this paragraph. In determining
the kind and amount of stock, securities or the property receivable upon
exercise of this Warrant following the consummation of such Business
Combination, if the holders of Common Stock have the right to elect the kind or
amount of consideration receivable upon consummation of such Business
Combination, then the consideration that the Warrantholder shall be entitled to
receive upon exercise shall be deemed to be the types and amounts of
consideration received by the majority of all holders of the shares of common
stock that affirmatively make an election (or of all such holders if none make
an election).

     (F)
Rounding of Calculations; Minimum
Adjustments. All calculations under this
Section 13 shall be made to the nearest one-tenth (1/10th) of a cent or to the
nearest one-hundredth (1/100th) of a share, as the case may be. Any provision of
this Section 13 to the contrary notwithstanding, no adjustment in the Exercise
Price or the number of Shares into which this Warrant is exercisable shall be
made if the amount of such adjustment would be less than $0.01 or one-tenth
(1/10th) of a share of Common Stock, but any such amount shall be carried
forward and an adjustment with respect thereto shall be made at the time of and
together with any subsequent adjustment which, together with such amount and any
other amount or amounts so carried forward, shall aggregate $0.01 or 1/10th of a
share of Common Stock, or more. 

     (G)
Timing of Issuance of Additional Common Stock
Upon Certain Adjustments. In any case in
which the provisions of this Section 13 shall require that an adjustment shall
become effective immediately after a record date for an event, the Company may
defer until the occurrence of such event (i) issuing to the Warrantholder of
this Warrant exercised after such record date and before the occurrence of such
event the additional shares of Common Stock issuable upon such exercise by
reason of the adjustment required by such event over and above the shares of
Common Stock issuable upon such exercise before giving effect to such adjustment
and (ii) paying to such Warrantholder any amount of cash in lieu of a fractional
share of Common Stock; provided, however, that the Company upon request
shall deliver to such Warrantholder a due bill or other appropriate instrument
evidencing such Warrantholder’s right to receive such additional shares, and
such cash, upon the occurrence of the event requiring such
adjustment. 

     (H)
Completion of Qualified Equity
Offering. In the event the Company (or any
successor by Business Combination) completes one or more Qualified Equity
Offerings on or prior to December 31, 2009 that result in the Company (or any
such successor ) receiving aggregate gross proceeds of not less than 100% of the
aggregate liquidation preference of the Preferred Shares (and any preferred
stock issued by any such successor to the Original Warrantholder under the CPP),
the number of shares of Common Stock underlying the portion of this Warrant then
held by the Original Warrantholder shall be thereafter reduced by a number of
shares of Common Stock equal to the product of (i) 0.5 and (ii) the number of
shares underlying the Warrant on the Issue Date (adjusted to take into account
all other theretofore made adjustments pursuant to this Section 13).

11 




     (I)
Other Events. For so long as the Original Warrantholder holds this Warrant or any
portion thereof, if any event occurs as to which the provisions of this Section
13 are not strictly applicable or, if strictly applicable, would not, in the
good faith judgment of the Board of Directors of the Company, fairly and
adequately protect the purchase rights of the Warrants in accordance with the
essential intent and principles of such provisions, then the Board of Directors
shall make such adjustments in the application of such provisions, in accordance
with such essential intent and principles, as shall be reasonably necessary, in
the good faith opinion of the Board of Directors, to protect such purchase
rights as aforesaid. The Exercise Price or the number of Shares into which this
Warrant is exercisable shall not be adjusted in the event of a change in the par
value of the Common Stock or a change in the jurisdiction of incorporation of
the Company. 

     (J)
Statement Regarding
Adjustments. Whenever the Exercise Price or
the number of Shares into which this Warrant is exercisable shall be adjusted as
provided in Section 13, the Company shall forthwith file at the principal office
of the Company a statement showing in reasonable detail the facts requiring such
adjustment and the Exercise Price that shall be in effect and the number of
Shares into which this Warrant shall be exercisable after such adjustment, and
the Company shall also cause a copy of such statement to be sent by mail, first
class postage prepaid, to each Warrantholder at the address appearing in the
Company’s records. 

     (K)
Notice of Adjustment Event. In the event that the Company shall propose to take any
action of the type described in this Section 13 (but only if the action of the
type described in this Section 13 would result in an adjustment in the Exercise
Price or the number of Shares into which this Warrant is exercisable or a change
in the type of securities or property to be delivered upon exercise of this
Warrant), the Company shall give notice to the Warrantholder, in the manner set
forth in Section 13(J), which notice shall specify the record date, if any, with
respect to any such action and the approximate date on which such action is to
take place. Such notice shall also set forth the facts with respect thereto as
shall be reasonably necessary to indicate the effect on the Exercise Price and
the number, kind or class of shares or other securities or property which shall
be deliverable upon exercise of this Warrant. In the case of any action which
would require the fixing of a record date, such notice shall be given at least
10 days prior to the date so fixed, and in case of all other action, such notice
shall be given at least 15 days prior to the taking of such proposed action.
Failure to give such notice, or any defect therein, shall not affect the
legality or validity of any such action.


     (L)
Proceedings Prior to Any Action Requiring
Adjustment. As a condition precedent to the
taking of any action which would require an adjustment pursuant to this Section
13, the Company shall take any action which may be necessary, including
obtaining regulatory, New York Stock Exchange or stockholder approvals or
exemptions, in order that the Company may thereafter validly and legally issue
as fully paid and nonassessable all shares of Common Stock that the
Warrantholder is entitled to receive upon exercise of this Warrant pursuant to
this Section 13. 

12 




     (M)
Adjustment Rules. Any adjustments pursuant to this Section 13 shall be made successively
whenever an event referred to herein shall occur. If an adjustment in Exercise
Price made hereunder would reduce the Exercise Price to an amount below par
value of the Common Stock, then such adjustment in Exercise Price made hereunder
shall reduce the Exercise Price to the par value of the Common
Stock. 

     14. Exchange. At any time following the
date on which the shares of Common Stock of the Company are no longer listed or
admitted to trading on a national securities exchange (other than in connection
with any Business Combination), the Original Warrantholder may cause the Company
to exchange all or a portion of this Warrant for an economic interest (to be
determined by the Original Warrantholder after consultation with the Company) of
the Company classified as permanent equity under U.S. GAAP having a value equal
to the Fair Market Value of the portion of the Warrant so exchanged. The
Original Warrantholder shall calculate any Fair Market Value required to be
calculated pursuant to this Section 14, which shall not be subject to the
Appraisal Procedure. 

     15. No
Impairment. The Company will not, by
amendment of its Charter or through any reorganization, transfer of assets,
consolidation, merger, dissolution, issue or sale of securities or any other
voluntary action, avoid or seek to avoid the observance or performance of any of
the terms to be observed or performed hereunder by the Company, but will at all
times in good faith assist in the carrying out of all the provisions of this
Warrant and in taking of all such action as may be necessary or appropriate in
order to protect the rights of the Warrantholder. 

     16. Governing Law. This Warrant will be governed by and construed in accordance
with the federal law of the United States if and to the extent such law is
applicable, and otherwise in accordance with the laws of the State of New York
applicable to contracts made and to be performed entirely within such State.
Each of the Company and the Warrantholder agrees (a) to submit to the exclusive
jurisdiction and venue of the United States District Court for the District of
Columbia for any action, suit or proceeding arising out of or relating to this
Warrant or the transactions contemplated hereby, and (b) that notice may be
served upon the Company at the address in Section 20 below and upon the
Warrantholder at the address for the Warrantholder set forth in the registry
maintained by the Company pursuant to Section 9 hereof. To the extent permitted
by applicable law, each of the Company and the Warrantholder hereby
unconditionally waives trial by jury in any legal action or proceeding relating
to the Warrant or the transactions contemplated hereby or
thereby. 

     17. Binding Effect. This Warrant shall be
binding upon any successors or assigns of the Company. 

     18. Amendments. This Warrant may be
amended and the observance of any term of this Warrant may be waived only with
the written consent of the Company and the Warrantholder. 

     19 .
Prohibited Actions. The Company agrees that it will not take any action which would entitle
the Warrantholder to an adjustment of the Exercise Price if the total number of
shares of Common Stock issuable after such action upon exercise of this Warrant,
together with all shares of Common Stock then outstanding and all shares of
Common Stock then issuable upon the exercise of all outstanding options,
warrants, conversion and other rights, would exceed the total number of shares
of Common Stock then authorized by its Charter.

13





     20. Notices. Any notice, request,
instruction or other document to be given hereunder by any party to the other
will be in writing and will be deemed to have been duly given (a) on the date of
delivery if delivered personally, or by facsimile, upon confirmation of receipt,
or (b) on the second business day following the date of dispatch if delivered by
a recognized next day courier service. All notices hereunder shall be delivered
as set forth in Item 8 of Schedule A hereto, or pursuant to such other
instructions as may be designated in writing by the party to receive such
notice. 

     21. Entire
Agreement. This Warrant, the forms attached
hereto and Schedule A hereto (the terms of which are incorporated by reference
herein), and the Letter Agreement (including all documents incorporated
therein), contain the entire agreement between the parties with respect to the
subject matter hereof and supersede all prior and contemporaneous arrangements
or undertakings with respect thereto. 

[Remainder of page intentionally left
blank] 

14 




[Form of Notice of
Exercise] 
Date: _________ 

	TO:	    	Enterprise
      Financial Services Corp
			 
	RE:		Election to
      Purchase Common Stock



     The
undersigned, pursuant to the provisions set forth in the attached Warrant,
hereby agrees to subscribe for and purchase the number of shares of the Common
Stock set forth below covered by such Warrant. The undersigned, in accordance
with Section 3 of the Warrant, hereby agrees to pay the aggregate Exercise Price
for such shares of Common Stock in the manner set forth below. A new warrant
evidencing the remaining shares of Common Stock covered by such Warrant, but not
yet subscribed for and purchased, if any, should be issued in the name set forth
below.

Number of Shares of Common
Stock

Method of Payment of Exercise Price
(note if cashless exercise pursuant to Section 3(i) of the Warrant or cash
exercise pursuant to Section 3(ii) of the Warrant, with consent of the Company
and the Warrantholder)

Aggregate Exercise Price: 


	Holder: 
    
	By: 

	Name: 
  
	Title: 
  




15 




     IN
WITNESS WHEREOF, the Company has caused this Warrant to be duly executed by a
duly authorized officer. 

Dated: December 19, 2008


	COMPANY:    
	  
	Enterprise
      Financial Services Corp  
	  
	By: 	     	/s/ Frank H. Sanfilippo 
  
	  	 	Name:  
    	Frank H.
      Sanfilippo  
	  		Title:  	Executive Vice
      President and  
	  		  	Chief Financial
      Officer  
	   
	   
	Attest:    
	  
	By: 	 	/s/ Noel J. Bortle  
	  		Name:   	Noel J. Bortle  
	  		Title:
      	Secretary 
  




[Signature Page to Warrant]


16 




SCHEDULE A 

Item 1
Name: Enterprise Financial Services Corp 
Corporate or other
organizational form: Corporation 
Jurisdiction of organization: Delaware 

Item 2 
Exercise Price: $16.20 

Item 3 
Issue Date: December 19, 2008


Item 4
Amount of last dividend declared prior to the Issue Date:
$.0525 per share per quarter 

Item 5 
Date of Letter Agreement between the
Company and the United States Department of the
Treasury: December 19, 2008 

Item 6
Number of shares of Common Stock: 324,074 

	Item
      7  	  
	Company’s
      address:   	Enterprise Financial
      Services Corp  
	  	150 N. Meramec
      Ave.  
	  	Clayton, Missouri
      63105  
	  
	Item
      8  	  
	Notice
      information:  	Attn: Frank H.
      Sanfilippo, Executive Vice President and Chief Financial Officer