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: ii

WPP plc

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

An acquisition or disposal of voting rights

YES

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

Massachusetts Financial Services Company

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

MFS invests in securities of the issuer on behalf of its various mutual funds and institutional clients.

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

3 May 2010

6. Date on which issuer notified:

5 May 2010

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

5%

8. Notified details:

A: Voting rights attached to shares viii, ix

Class/type of shares

if possible using the ISIN CODE

Situation previous to the triggering transaction

Resulting situation after the triggering transaction

Number of Shares

Number of Voting Rights

Number of shares

Number of voting rights

% of voting rights x

Direct

Direct xi

Indirect xii

Direct

Indirect

JE00B3DMTY01

81,430,027

81,430,027

62,512,490

4.98%

B: Qualifying Financial Instruments

Resulting situation after the triggering transaction

Type of financial instrument

Expiration date xiii

Exercise/ Conversion Period xiv

Number of voting rights that may be acquired if the instrument is exercised/ converted.

% of voting rights

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

Resulting situation after the triggering transaction

Type of financial instrument

Exercise price

Expiration date xvii

Exercise/ Conversion period xviii

Number of voting rights instrument refers to

% of voting rights xix, xx

Nominal

Delta

Total (A+B+C)

Number of voting rights

Percentage of voting rights

62,512,490

4.98%

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

WPP PLC - B3DMTY0

Holdings as of 3 May 2010

Entity Holding Percentage Held

MFS Investment Management (MFS) 24,669,896 1.96%

MFS Heritage Trust Company (MFSHE) 314,181 0.02%

MFS Institutional Advisors, Inc. (MFSI) 14,271,084 1.14%

MFS International Ltd. (MIL) 4,090,353 0.33%

MFS International (U.K.) Limited (MIL U.K.) 11,855,607 0.94%

MFS International Management K.K. (MIM K.K.) 5,098,147 0.41%

MFS Investment Management (Lux) S.A. (MIM Lux) 2,213,222 0.18%

Notifiable Interest 62,512,490 4.98%

Shares Outstanding 1,255,656,885

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:

14. Contact name:

Marie Capes, WPP plc

15. Contact telephone number:

020 7408 2204