OPP.L Regulatory News (OPP)

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

Origo Partners plc

Sedol B1G3MS1

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

An acquisition or disposal of voting rights

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):

X

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

Ecofin Limited

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

Ecofin Water & Power Opportunities plc - 27,396,364 shares (9.05%)

Ecofin Special Situations Utilities Master Fund Limited - 2,739,636 shares (0.91%)

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

17 June 2010

6. Date on which issuer notified:

1 July 2010

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

3%

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

Ordinary shares

30,136,000

30,136,000

30,136,000

30,136,000

30,136,000

IM00B1G3MS12

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

30,136,000

9.97%

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

Ecofin Water & Power Opportunities plc - 27,396,364 shares (9.05%)

Ecofin Special Situations Utilities Master Fund Limited - 2,739,636 shares (0.91%)

Proxy Voting:

10. Name of the proxy holder:

Ecofin Limited

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:

14. Contact name:

Rich Morris

15. Contact telephone number:

+44 (0) 20 7451 2929

Note: Annex should only be submitted to the FSA not the issuer

Annex: Notification of major interests in share

A: Identity of the persons or legal entity subject to the notification obligation

Full name

(including legal form of legal entities)

Origo Partners plc

Contact address

(registered office for legal entities)

26th Floor, Building A, North Tower, SOHO Shangdu, No.8 Dongdaqiao Road,, Beijing, 100020, China

Phone number & email

Other useful information

(at least legal representative for legal persons)

B: Identity of the notifier, if applicable

Full name

Ecofin Limited

Contact address

Burdett House

15 Buckingham St.

London, WC2N 6DU

Phone number & email

Rich Morris / rmorris@ecofin.co.uk

Other useful information

(e.g. functional relationship with the person or legal entity subject to the notification obligation)

C: Additional information

For notes on how to complete form TR-1 please see the FSA website.