Holding(s) in Company

1. Identity of the issuer or the underlying issuer of existing shares to which voting rights are attached: ii

Great Portland Estates Plc

2 Reason for the notification (please tick the appropriate box or boxes):

An acquisition or disposal of voting rights

X

An acquisition or disposal of qualifying financial instruments which may result in the acquisition of shares already issued to which voting rights are attached

An acquisition or disposal of instruments with similar economic effect to qualifying financial instruments

An event changing the breakdown of voting rights

Other (please specify):

3. Full name of person(s) subject to the notification obligation: iii

Harbor International Fund

a series of Harbor Funds, a Delaware Statutory Trust

4. Full name of shareholder(s)  (if different from 3.):iv

5. Date of the transaction and date on which the threshold is crossed or reached: v

May 18, 2017

6. Date on which issuer notified:

June 1, 2017

7. Threshold(s) that is/are crossed or reached: vi, vii

3% of issuer's voting rights

8. Notified details:

A: Voting rights attached to shares viii, ix

Class/type ofshares

if possible usingthe ISIN CODE

Situation previousto the triggeringtransaction

Resulting situation after the triggering transaction

NumberofShares

NumberofVotingRights

Numberof shares

Number of votingrights

% of voting rights x

Direct

Direct xi

Indirect xii

Direct

Indirect

Common

SEDOL: BZ0XJR3

12,254,326

12,254,326

11,641,609.7

11,641,609.7

N/A

3.56%

N/A

B: Qualifying Financial Instruments

Resulting situation after the triggering transaction

Type of financialinstrument

Expirationdate xiii

Exercise/Conversion Period xiv

Number of votingrights that may beacquired if theinstrument isexercised/ converted.

% of votingrights

N/A

N/A

N/A

N/A

N/A

C: Financial Instruments with similar economic effect to Qualifying Financial Instruments xv, xvi

Resulting situation after the triggering transaction

Type of financialinstrument

Exercise price

Expiration date xvii

Exercise/Conversion period xviii

Number of voting rights instrument refers to

% of voting rights xix, xx

N/A

N/A

N/A

N/A

N/A

Nominal

Delta

N/A

N/A

Total (A+B+C)

Number of voting rights

Percentage of voting rights

11,641,609.7

3.56%

9. Chain of controlled undertakings through which the voting rights and/or thefinancial instruments are effectively held, if applicable: xxi

N/A

Proxy Voting:

10. Name of the proxy holder:

N/A

11. Number of voting rights proxy holder will cease to hold:

N/A

12. Date on which proxy holder will cease to hold voting rights:

N/A

13. Additional information:

Completed in Chicago, Illinois, USA

on June 1, 2017

14. Contact name:

Jodie L. Crotteau

Assistant Secretary

15. Contact telephone number:

312-443-4428