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:

WS Atkins plc

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

An acquisition or disposal of voting rights

No

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):

Voluntary baseline disclosure in line with the UK implementation of the Amended Transparency Directive

Yes

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

Ameriprise Financial, Inc. and its group

4. Full name of shareholder(s)

(if different from 3.):

State Street Nominees Limited

Nortrust Nominees LTD

Vidacos Nominees Ltd

HSBC Global Custody Nominee (UK) Limited

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

N/A - Voluntary baseline disclosure in line with the UK implementation of the Amended Transparency Directive

6. Date on which issuer notified:

30th November 2015

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

reached:

Voluntary baseline disclosure in line with the UK implementation of the Amended Transparency Directive

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

10,007,713

10,007,713

0

0

8,116,169

0.000%

8.107%

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

Nominal

Delta

Total (A+B+C)

Number of voting rights

Percentage of voting rights

8,116,169

8.107%

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

Threadneedle Asset Management Limited (8.107%)

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 cease to hold:

N/A

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

15. Contact telephone number:

+44 (0) 1793 363 135