Holding(s) in Company

TR-1: NOTIFICATION OF MAJOR INTEREST IN SHARES

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

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

X

An event changing the breakdown of voting rights

Other (please specify):

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

BlackRock, Inc.

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

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

22nd February 2011

6. Date on which issuer notified:

23rd February 2011

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

Holding has gone below 10%

8. Notified details:

A: Voting rights attached to shares

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

Direct

Direct

Indirect

Direct

Indirect

GB00B01FLL16

29,454,761

29,454,761

N/A

N/A

28,306,596

N/A

9.05%

B: Qualifying Financial Instruments

Resulting situation after the triggering transaction

Type of financialinstrument

Expirationdate

Exercise/ConversionPeriod

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

% of votingrights

C: Financial Instruments with similar economic effect to Qualifying Financial Instruments

Resulting situation after the triggering transaction

Type of financialinstrument

Exerciseprice

Expirationdate

Exercise/Conversionperiod

Number of votingrights instrumentrefers to

% of voting rights

CFD

2,630,418

Nominal

Delta

0.84%

0.84%

Total (A+B+C)

Number of voting rights

Percentage of voting rights

30,937,014

9.89%

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

 BlackRock Investment Management (UK) Limited - 30,937,014 (9.89%)

Proxy Voting:

10. Name of the proxy holder:

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

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

13. Additional information:

BlackRock International Threshold Reporting Team

14. Contact name:

Andrew Manchester

15. Contact telephone number:

020 7743 5773;

[email protected]