Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
Asensio Robert John
   2. Issuer Name and Ticker or Trading Symbol
Darwin Professional Underwriters Inc [DR] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
S.V.P. -- Chief Info. Officer
(Last)
(First)
(Middle)
9 FARM SPRINGS ROAD		 3. Date of Earliest Transaction (Month/Day/Year)
08/10/2007
(Street)

FARMINGTON, CT 06032		 4. If Amendment, Date Original Filed(Month/Day/Year)
 6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)		 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)		 4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)		 5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)		 6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)		 7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Stock 08/10/2007   S   9,300 (1) D $ 22.0232 (1) 96,253 D  
Common Stock 08/13/2007   S   7,600 (2) D $ 22.2327 (2) 88,653 D  

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)		 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)		 5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)		 6. Date Exercisable and Expiration Date
(Month/Day/Year)		 7. Title and Amount of Underlying Securities
(Instr. 3 and 4)		 8. Price of Derivative Security
(Instr. 5)		 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)		 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)		 11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
Asensio Robert John
9 FARM SPRINGS ROAD
FARMINGTON, CT 06032		       S.V.P. -- Chief Info. Officer  

Signatures

 Robert J. Asensio by Timothy J. Curry, attorney in fact   08/14/2007
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) On August 10, 2007, Mr. Asensio sold a total of 9,300 shares of common stock of Darwin Professional Underwriters, Inc. in a series consisting of eight individual transactions, as follows: 300 shares at $22.30 each; 100 shares at $22.20 each; 100 shares at 22.16 each; 200 shares at 22.12 each; 400 shares at 22.09; 400 shares at 22.06 each; 600 shares at 22.01 each; and 7,200 shares at 22.00 each. The weighted average price per share for the August 10th sales was $22.0232.
(2) On August 13, 2007, Mr. Asensio sold a total of 7,600 shares of common stock of Darwin Professional Underwriters, Inc. in a series consisting of seventeen individual transactions, as follows: 300 shares at $22.45; 200 shares at $22.37; 500 shares at $22.05; 2,100 shares at $22.15; 500 shares at $22.09; 200 shares at $22.13; 100 shares at $21.125; 700 shares at $22.10; 400 shares @ $22.07; 100 shares at $22.06; 500 shares @ $22.00; 100 shares @ $22.42; 700 shares at $22.43; 100 shares @ $22.69; 100 shares at $22.68; 698 shares at $22.54; and 302 shares at $22.58. The weighted average price per share for the August 23th sales was $22.2327.

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