SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* HARTZBAND MERYL D (Last) (First) (Middle) C/O ALTERRA CAPITAL HOLDINGS LIMITED ALTERRA HOUSE, 2 FRONT STREET (Street) HAMILTON, BERMUDA D0 HM 11 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol ALTERRA CAPITAL HOLDINGS Ltd [ ALTE ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X Director 10% Owner Officer (give title below) Other (specify below)
	3. Date of Earliest Transaction (Month/Day/Year) 12/05/2012
	4. If Amendment, Date of 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

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

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 Securities Underlying Derivative Security (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: 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
Warrants (right to buy)	$18.683	12/05/2012		A		34,674.77(1)(2)(3)		(4)	12/15/2015	Common Shares	34,674.77	(1)(2)(3)	5,095,836.41(1)(2)(3)	I	By Trident III Professionals Fund, L.P. and Trident III, L.P.(1)(2)(3)

Explanation of Responses:

1. Filing is made in respect of warrants to purchase common shares of Alterra Capital Holdings Limited ("Alterra") held by Trident III Professionals Fund, L.P. and Trident III, L.P. Ms. Hartzband is a member and senior principal of Stone Point Capital LLC, a shareholder and a director of Stone Point GP Ltd., which is the general partner of Trident III Professionals Fund, L.P., and a member of the investment committee and owner of one of the five general partners of Trident Capital III, L.P., which is the general partner of Trident III, L.P. Ms. Hartzband disclaims beneficial ownership of the common shares of Alterra held of record or beneficially by Trident III Professionals Fund, L.P. and Trident III, L.P., except as to the extent of any pecuniary interest therein.

2. Pursuant to the anti-dilution provisions of warrants to purchase common shares of Alterra held by Trident III Professionals Fund, L.P. and Trident III, L.P., following the declaration of a dividend by Alterra, (i) each of Trident III Professionals Fund, L.P. and Trident III, L.P. is entitled to elect to receive a payment in cash in respect of such dividend for each common share of Alterra purchased pursuant to the warrants (such payment to be made at the time of exercise of the warrants), or (ii) if Trident III Professionals Fund, L.P. and Trident III, L.P. make no election, each of Trident III Professionals Fund, L.P. and Trident III, L.P. will receive an adjustment to the exercise price of the warrants held by them (and a resulting change to the number of common shares of Alterra for which its warrants are exercisable) following the record date for such dividend.

3. On December 5, 2012, the exercise price of the warrants held by Trident III Professionals Fund, L.P. and Trident III, L.P. adjusted (and a resulting adjustment was made to the number of common shares for which its warrants are exercisable) in respect of the $0.16 per share dividend declared by Alterra to holders of record of common shares of Alterra as of November 20, 2012. Pursuant to this adjustment, the exercise price of the warrants held by each of Trident III Professionals Fund, L.P. and Trident III, L.P. was reduced from $18.811 to $18.683 and (a) Trident III Professionals Fund, L.P. became entitled to exercise its warrants for an additional 821.11 common shares of Alterra and (b) Trident III, L.P. became entitled to exercise its warrants for an additional 33,853.66 common shares of Alterra.

4. All warrants are immediately exercisable.

Remarks:

	Bernard Asirifi, Attorney-in-Fact	12/05/2012
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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