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 *
THERO JOHN F
  2. Issuer Name and Ticker or Trading Symbol
AMARIN CORP PLC\UK [AMRN]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
President
(Last)
(First)
(Middle)
C/O AMARIN PHARMA, INC., 1430 ROUTE 206, SUITE 200
3. Date of Earliest Transaction (Month/Day/Year)
07/26/2012
(Street)

BEDMINSTER, NJ 07921
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
Ordinary Shares (1) 07/26/2012   A   9,450 A $ 0 (2) 9,450 D  
Ordinary Shares (1) 07/27/2012   M   150,926 A $ 1.35 160,376 (10) D  
Ordinary Shares (1) 07/27/2012   S(5)   150,926 D $ 14.97 (6) 9,450 D  
Ordinary Shares (1) 07/27/2012   M   150,000 A $ 3.4 159,450 D  
Ordinary Shares (1) 07/27/2012   S(5)   150,000 D $ 13.71 (7) 9,450 D  

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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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
Restricted Stock Units $ 0 (4) 07/26/2012   A   9,450     (3)   (3) Ordinary Shares (1) 9,450 $ 0 9,450 D  
Ordinary Shares (1) $ 1.35 07/27/2012   M     150,926   (8) 12/21/2019 Ordinary Shares (1) 150,926 $ 0 448,611 (11) D  
Ordinary Shares (1) $ 3.4 07/27/2012   M     150,000   (9) 11/10/2020 Ordinary Shares (1) 150,000 $ 0 750,000 (12) D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
THERO JOHN F
C/O AMARIN PHARMA, INC.
1430 ROUTE 206, SUITE 200
BEDMINSTER, NJ 07921
      President  

Signatures

 /s/ Frederick Ahlholm, by power of attorney   07/30/2012
**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) The Ordinary Shares may be represented by American Depositary Shares, each of which currently represents one Ordinary Share.
(2) On February 1, 2012, the Reporting Person was granted 56,700 restricted stock units (the "RSUs") under the Amarin Corporation plc 2011 Stock Incentive Plan. Each RSU represents a contingent right to receive one Ordinary Share or cash in lieu thereof at the Issuer's discretion. The RSUs vest in six equal installments based on the Issuer's satisfaction of certain performance criteria and continued employment of the Reporting Person as provided in the Restricted Stock Unit Award Agreement between the Issuer and the Reporting Person. The performance criteria for the first installment was met, resulting in vesting of 9,450 RSUs.
(3) These RSUs vest on July 26, 2013, subject to continued employment of the Reporting Person through such date. Ordinary Shares will be delivered to the Reporting Person as soon as practicable after the vesting date.
(4) Each RSU represents a contingent right to receive one Ordinary Share or cash in lieu thereof at the Issuer's discretion.
(5) The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on June 13, 2012.
(6) The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $14.73 to $15.36, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range.
(7) The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $13.61 to $13.83, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range.
(8) On December 21, 2009, the Reporting Person was granted an option to purchase 900,000 Ordinary Shares under the Amarin Corporation plc 2002 Stock Option Plan. The stock option vests in four equal installments on December 21, 2010, June 21, 2011, June 21, 2012 and June 21, 2013.
(9) On November 10, 2010, the Reporting Person was granted an option to purchase 1,200,000 Ordinary Shares under the Amarin Corporation plc 2002 Stock Option Plan. The stock option will vest in four equal annual installments on November 11, 2010, November 10, 2011, November 10, 2012 and November 10, 2013.
(10) Since the date of the Reporting Person's last ownership report, he partially exercised the option granted December 21, 2009 in order to purchase 37,500 Ordinary Shares and transferred such Ordinary Shares to his ex-wife, all pursuant to a domestic relations order. The Reporting Person no longer reports as beneficially owned any securities owned by his ex-wife.
(11) Since the date of the Reporting Person's last ownership report, he (i) partially exercised the option to purchase 37,500 Ordinary Shares and transferred such Ordinary Shares to his ex-wife, and (b) transferred the option to purchase 112,037 Ordinary Shares under the December 21, 2009 award to his ex-wife, all pursuant to a domestic relations order. The Reporting Person no longer reports as beneficially owned any securities owned by his ex-wife.
(12) Since the date of the Reporting Person's last ownership report, he transferred the option to purchase 300,000 Ordinary Shares under the November 10, 2012 award pursuant to a domestic relations order. The Reporting Person no longer reports as beneficially owned any securities owned by his ex-wife.

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