Holding(s) in Company

TR-1: NOTIFICATION OF MAJOR INTEREST IN SHARES

1. Identity of the issuer or the underlying issuerof existing shares to which voting rights areattached:

WS Atkins 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

NO

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

NO

An event changing the breakdown of voting rights

NO

Other (please specify):

NO

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

Ameriprise Financial, Inc. and its group

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

HSBC Global Custody Nominees (UK) Ltd

State Street Nominees Limited

Vidacos Nominees Ltd

5. Date of the transaction and date onwhich the threshold is crossed orreached:

27th June 2017

6. Date on which issuer notified:

28th June 2017

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

Below the threshold of 5%

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

GB0000608009

8,116,169

8,116,169

0

0

3,878,435

0.000%

3.874%

B: Qualifying Financial Instruments

Resulting situation after the triggering transaction

Type of financialinstrument

Expirationdate

Exercise/Conversion Period

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

Exercise price

Expiration date

Exercise/Conversion period

Number of voting rights instrument refers to

% of voting rights

Nominal

Delta

Total (A+B+C)

Number of voting rights

Percentage of voting rights

3,878,435

3.874%

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

Threadneedle Asset Management Limited (3.874%)

Threadneedle Asset Management Limited is wholly owned by TC Financing Limited, which is itself wholly owned by Threadneedle Asset Management Holdings Limited, which is itself wholly owned by TAM UK Holdings Limited, which is itself wholly owned by Threadneedle Holdings Limited, which is itself wholly owned by Threadneedle Asset Management Holdings SARL, which is itself wholly owned by Ameriprise International Holdings GmbH, which is itself wholly owned by Ameriprise Financial, Inc.

Proxy Voting:

10. Name of the proxy holder:

N/A

11. Number of voting rights proxy holder will ceaseto hold:

N/A

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

N/A

13. Additional information:

The Shares referred to in section 9 of this form are held in portfolios and funds managed on a discretionary basis by the entities set out in section 9.

Please note that the Shares are held through certain nominee companies.

14. Contact name:

Mark Powney, Threadneedle Asset Management Ltd.

15. Contact telephone number:

+44 (0) 1793 363 135