SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549


                                  SCHEDULE 13G
                                 (Rule 13d-102)

             INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT
            TO RULES 13d-1(b),(c), AND (d) AND AMENDMENTS THERETO FILED
                             PURSUANT TO RULE 13d-2(b)
                                (Amendment No. 2)*


                          	Acuity Brands Inc
--------------------------------------------------------------------------------
                                (Name of Issuer)


                                   Common Stock
--------------------------------------------------------------------------------
                         (Title of Class of Securities)


                                    00508Y102
--------------------------------------------------------------------------------
                                 (CUSIP Number)


                                31 December 2009
--------------------------------------------------------------------------------
             (Date of Event Which Requires Filing of this Statement)


Check the  appropriate box to designate the rule pursuant to which this Schedule
is filed:

[X]  Rule 13d-1(b)
[ ]  Rule 13d-1(c)
[ ]  Rule 13d-1(d)

--------------------------------------------------------------------------------
1 The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities,
and for any subsequent amendment containing information which would alter the
disclosures provided in a prior cover page.
The information required in the remainder of this cover page shall not be
deemed to be "filed" for the purpose of Section 18 of the Securities Exchange
Act of 1934 (the "Act") or otherwise subject to the liabilities of that section
of the Act, but shall be subject to all other provisions of the Act (however,
see the Notes.)

                         (Continued on following pages)

                                Page 1 of 6 Pages







CUSIP No. 00508Y102            Schedule 13G                 Page 2 of 6 Pages
          -----------        --------------

1.       NAMES OF REPORTING PERSONS
         I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

         M&G Investment Management Limited
         No I.R.S Identification Number
--------------------------------------------------------------------------------
2.       CHECK THE APPROPRIATE BOX IF THE MEMBER OF A GROUP*
                                                                 (a)  [ ]
                                                                 (b)  [ ]
--------------------------------------------------------------------------------
3.       SEC USE ONLY
--------------------------------------------------------------------------------
4.       CITIZENSHIP OR PLACE OF ORGANIZATION
         United Kingdom, England
--------------------------------------------------------------------------------
                     5.   SOLE VOTING POWER
NUMBER OF                 0
SHARES              ------------------------------------------------------------
BENEFICIALLY         6.   SHARED VOTING POWER
OWNED BY                  3,287,363

EACH                ------------------------------------------------------------
REPORTING            7.   SOLE DISPOTIVE POWER
PERSON                    0
WITH                ------------------------------------------------------------
                     8.   SHARED DISPOTIVE POWER
                          3,287,363
--------------------------------------------------------------------------------
9.       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
         3,287,363
--------------------------------------------------------------------------------
10.      CHECK BOX IF AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN
         SHARES*                                              [_]
--------------------------------------------------------------------------------
11.      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
         7.59%
--------------------------------------------------------------------------------
12.      TYPE OF REPORTING PERSON
         IA
--------------------------------------------------------------------------------









CUSIP No. 00508Y102           Schedule 13G                 Page 3 of 6 Pages
          -----------        --------------

1.       NAMES OF REPORTING PERSONS
         I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

         M&G Investment Funds 1
         No I.R.S Identification Number
--------------------------------------------------------------------------------
2.       CHECK THE APPROPRIATE BOX IF THE MEMBER OF A GROUP*
                                                                 (a)  [ ]
                                                                 (b)  [ ]
--------------------------------------------------------------------------------
3.       SEC USE ONLY
--------------------------------------------------------------------------------
4.       CITIZENSHIP OR PLACE OF ORGANIZATION
         United Kingdom, England
--------------------------------------------------------------------------------
                     5.   SOLE VOTING POWER
NUMBER OF                 0
SHARES              ------------------------------------------------------------
BENEFICIALLY         6.   SHARED VOTING POWER
OWNED BY                  3,275,000

EACH                ------------------------------------------------------------
REPORTING            7.   SOLE DISPOTIVE POWER
PERSON                    0
WITH                ------------------------------------------------------------
                     8.   SHARED DISPOTIVE POWER
                          3,275,000
--------------------------------------------------------------------------------
9.       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
         3,275,000
--------------------------------------------------------------------------------
10.      CHECK BOX IF AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN
         SHARES*                                              [_]
--------------------------------------------------------------------------------
11.      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
         7.56%
--------------------------------------------------------------------------------
12.      TYPE OF REPORTING PERSON
         OO
--------------------------------------------------------------------------------




CUSIP No. 00508Y102           Schedule 13G                 Page 4 of 6 Pages
          -----------        --------------
Item 1(a).   Name of Issuer:

                  Acuity Brands Inc.

Item 1(b).   Address of Issuer's Principal Executive Offices:

1170 Peachtree Street NE, Suite 2400, Atlanta, GA 30309, United States

Item 2(a).   Name of Person Filing:

              1.  M&G Investment Management Limited (MAGIM)
              2.  M&G Investment Funds 1

Item 2(b).   Address of Principal Business Office or, if None,
             Residence:

                  Governor's House, Laurence Pountney Hill, London, EC4R 0HH

Item 2(c).   Citizenship:

                  United Kingdom, England

Item 2(d).   Title of Class of Securities:

                  Common Stock

Item 2(e).   CUSIP Number:

                  00508Y102

Item 3.		Type of Person:
         MAGIM is an investment advisor in accordance with
         s.240.13d-1(b)(1)(ii)(E)

All the securities covered by this report are legally owned by
MAGIM's Investment advisory clients, and none are owned directly by
MAGIM.

Item 4.      Ownership.
             Provide the following information regarding the aggregate
             number and percentage of the class of securities of the issuer
             identified in Item 1.

(a) Amount Beneficially Owned: M&G, in its capacity as investment manager,
      may be deemed to beneficially owned: 3,287,363 shares

        (b)  Percent of Class: 7.59%

        (c)  Number of shares as to which such person has:
          M&G Investment Management Limited
               (i)    sole power to vote or to direct the vote  0
                                                                ----------
               (ii)   shared power to vote or to direct the
                      vote                                      3,287,363
                                                                ----------
               (iii)  sole power to dispose or to direct the
                      disposition of                            0
                                                                ----------
               (iv)   shared power to dispose or to direct the
                      disposition of                            3,287,363
                                                                ----------
         M&G Investment Funds (1)
               (i)    sole power to vote or to direct the vote  0
                                                                ----------
               (ii)   shared power to vote or to direct the
                      vote                                      3,275,000
                                                                ----------
               (iii)  sole power to dispose or to direct the
                      disposition of                            0
                                                                ----------
               (iv)   shared power to dispose or to direct the
                      disposition of                            3,275,000
                                                                ----------








CUSIP No. 00508Y102          Schedule 13G                 Page 5 of 6 Pages
          -----------        --------------

Item 5.      Ownership of Five Percent or Less of Class.
             If this statement is being filed to report the fact that as of the
             date hereof the reporting person has ceased to be the beneficial
             owner of more than five percent of the class of securities, check
             the following

             Not applicable.

Item 6.      Ownership of More than Five Percent on Behalf of Another
             Person.

             Not applicable.

Item 7.      Identification and Classification of the Subsidiary Which
             Acquired the Security Being Reported on by the Parent Holding
             Company.

             Not applicable.

Item 8.      Identification and Classification of Members of the Group.


             Not applicable.


Item 9.      Notice of Dissolution of Group.

             Not Applicable








CUSIP No. 00508Y102           Schedule 13G                 Page 6 of 6 Pages
          -----------         --------------


Item 10.     Certification.
             -------------

          (a) The following certification shall be included if the statement
          is filed pursuant to Rule 13d-1(b):

          "By signing below I certify that, to the best of my knowledge
          and belief, the securities referred to above were acquired
          and are held in the ordinary course of business and were not
          acquired and are not held for the purpose of or with the
          effect of changing or influencing the control of the issuer of
          the securities and were not acquired and are not held in
          connection with or as a participant in any transaction
          having that purpose or effect. "


                                    SIGNATURE


          After reasonable inquiry and to the best of my knowledge and belief,
          I certify that the information set forth in this statement is true,
          complete and correct.


                                By:  --//Mark Thomas//--
                                     --------------------------------------
                                Name:    Mark Thomas
                                Title:   Head of Group Funds
                                Date:    February 04, 2010

Exhibit A

AGREEMENT OF JOINT FILING

In accordance with Rule 13d-1(k) under the Securities Exchanges
Act of 1934, as amended, the undersigned hereby agrees that the
foregoing statement on Schedule 13G/A, is filed on behalf of each
of the undersigned without the necessity of filing additional
joint acquisition statements.  The undersigned acknowledge that
each shall be responsible for the timely filing of such
amendments, and for the completeness and accuracy of information
concerning the others, except to the extent that he or it knows
or has reason to believe that such information is inaccurate.

IN WITNESS WHEREOF, the undersigned hereby execute this Agreement
on the 4th day of February, 2010.

					M&G INVESTMENT MANAGEMENT LIMITED

					By  /s/ Mark Thomas
Date:  February 04, 2010	Head of Group Funds



					M&G Investment Funds 1

					By  /s/ Mark Thomas
Date:  February 04, 2010	Head of Group Funds