Seagate Technology — Director's Dealing 2011

Nov 8, 2011

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: Seagate Technology plc (STX)
CIK: 0001137789
Period of Report: 2011-11-04

Reporting Person: MOSLEY WILLIAM D (EVP, Sales and Marketing)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2011-11-04	Ordinary Shares	M	100000	$4.045	Acquired	122290.5977	Direct
2011-11-04	Ordinary Shares	S	100000	$18.00	Disposed	22290.5977	Direct
2011-11-07	Ordinary Shares	M	19814	$13.73	Acquired	42104.5977	Direct
2011-11-07	Ordinary Shares	S	19814	$18.50	Disposed	22290.5977	Direct
2011-11-07	Ordinary Shares	M	1019	$13.73	Acquired	23309.5977	Direct
2011-11-07	Ordinary Shares	M	10000	$4.045	Acquired	33309.5977	Direct
2011-11-07	Ordinary Shares	S	11019	$18.5	Disposed	22290.5977	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2011-11-04	NQ Stock Option	$4.045	M	100000	Disposed	2016-01-30	Ordinary Shares (100000)	Direct
2011-11-04	NQ Stock Option	$13.73	M	19814	Disposed	2015-09-12	Ordinary Shares (19814)	Direct
2011-11-07	NQ Stock Option	$13.73	M	1019	Disposed	2015-09-12	Ordinary Shares (1019)	Direct
2011-11-07	NQ Stock Option	$4.045	M	10000	Disposed	2016-01-30	Ordinary Shares (10000)	Direct

Footnotes

F1: Includes 686 shares purchased under the employee stock purchase plan on July 29, 2011.

F2: On July 8, 2011, the Compensation Committee of the Board of Directors of the Issuer authorized and confirmed that the performance metrics were met with respect to 5,500 of the 22,000 Performance Shares granted to Mr. Mosley on September 13, 2010 and reported on Mr. Mosley's Form 4 dated September 15, 2010.

F3: The Sale reported on this Form 4 was affected by a 10b5-1 trading plan adopted by the Reporting Person on May 24, 2011.

F4: The Sale reported on this Form 4 was affected by a 10b5-1 trading plan adopted by the Reporting Person on February 22, 2011.

F5: Options granted to the Reporting Person under the 2004 Stock Compensation Plan are subject to a four-year vesting schedule. One quarter of the shares vested on January 30, 2010. The remaining shares vest proportionally each month over the 36 months following January 30, 2010.

F6: Options granted to the Reporting Person under the 2004 Stock Compensation Plan and are subject to a four-year vesting schedule. One quarter of the shares vested as of September 12, 2009. The remainder of the shares vested proportionally each month over the 36 months following September 12, 2009.