Sec Form 4 Filing - REYES GREGORIO @ Seagate Technology plc - 2012-08-09

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 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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1. Name and Address of Reporting Person REYES GREGORIO 2. Issuer Name and Ticker or Trading Symbol Seagate Technology plc [ STX] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) SEAGATE TECHNOLOGY PLC, 10200 S. DE ANZA BOULEVARD 3. Date of Earliest Transaction (MM/DD/YY) 08/09/2012 (Street) CUPERTINO, CA95014 4. If Amendment, Date Original Filed (MM/DD/YY) 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 (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 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 08/09/2012 M 25,000 A $ 22.695 44,468 D Ordinary Shares 08/09/2012 M 7,500 A $ 6.525 51,968 D Ordinary Shares 08/09/2012 M 5,000 A $ 14.825 56,968 D Ordinary Shares 08/09/2012 S 37,500 D $ 33.0827 ( 1 ) 19,468 D Ordinary Shares 31,488 I Gregorio and Vancessa Reyes Trust

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 (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 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 (MM/DD/YY) 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 NQ Stock Options $ 22.695 08/09/2012 M 25,000 10/26/2007( 2 ) 10/26/2013 Ordinary Shares 25,000 $ 0 0 D NQ Stock Options $ 6.525 08/09/2012 M 7,500 10/15/2009( 3 ) 10/30/2015 Ordinary Shares 7,500 $ 0 2,500 D NQ Stock Options $ 14.825 08/09/2012 M 5,000 10/15/2010( 4 ) 10/28/2016 Ordinary Shares 5,000 $ 0 5,000 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other REYES GREGORIO SEAGATE TECHNOLOGY PLC 10200 S. DE ANZA BOULEVARD CUPERTINO, CA95014 X Signatures /S/ Roberta S. Cohen for Gregorio Reyes 08/13/2012 Signature of Reporting Person Date

Explanation of Responses:

( 1 )The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at sales prices ranging from $33.04 to $33.125, 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 set forth in this footnote. ( 2 )Options granted to the Reporting Person under the Issuer's 2004 Stock Compensation Plan were subject to a four-year vesting schedule. One quarter of the shares vested on October 26, 2007. The remaining three quarters vested proportionally annually on October 26 over the three years thereafter. ( 3 )Options granted to the Reporting Person under the Issuer's 2004 Stock Compensation Plan are subject to a four-year vesting schedule. One quarter of the shares vested on October 15, 2009. The remaining options are vesting and will continue to vest proportionally each month over the 36 months following October 15, 2009. ( 4 )Options granted to the Reporting Person under the Issuer's 2004 Stock Compensation Plan are subject to a four-year vesting schedule. One quarter of the shares vested on October 15, 2010.The remaining options are vesting and will continue to vest proportionally each month over the 36 months following October 15, 2010.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* 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).

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