Seagate: Announcement Relevant Securities in Issue

In accordance with Rule 2.10 of the Irish Takeover Panel Act, 1997, Takeover Rules, 2007 (as amended), Seagate Technology plc confirms that, as at close of business on 17 November 2010, its issued share capital comprised 472,795,377 ordinary shares of US$0.00001 each. The International Securities Identification Number for these securities is IE00B58JVZ52.

The Company also confirms that, at the close of business on 17 November 2010, there are 54,869,005 share options, 2,305,448 restricted share units and 648,620 performance units that have been granted by the Company and which are currently outstanding.

The directors of Seagate accept responsibility for the information contained in this announcement. To the best of the knowledge and belief of the directors of Seagate (who have taken all reasonable care to ensure that such is the case), the information contained in this announcement is in accordance with the facts and does not omit anything likely to affect the import of such information.

Any holder of 1% or more of any class of relevant securities in the Company may from the date of this announcement have disclosure obligations under Rule 8.3 of the Irish Takeover Panel Act, 1997, Takeover Rules 2007 (as amended).

Morgan Stanley Co. Incorporated and certain of its associated entities and Perella Weinberg Partners LP and certain of its associated entities are acting as financial advisers to Seagate and no one else in connection with the matters set out in this announcement and will not be responsible to anyone other than Seagate for providing the protections afforded to the clients of Morgan Stanley or Perella Weinberg Partners, respectively, nor for providing advice in relation to the contents of this announcement or any other matter referred to herein.