Holding(s) in Company

AstraZeneca PLC
21 March 2007


TR-1: NOTIFICATION OF MAJOR INTERESTS IN SHARES

1. Identity of the issuer or the underlying issuer of existing shares to which
voting rights are attached:

AstraZeneca PLC

2. Reason for the notification (place an X inside the appropriate bracket/s)

An acquisition or disposal of voting rights: (    )

An acquisition or disposal of financial instruments which may result in the
acquisition of shares already issued to which voting rights are attached: (    )

An event changing the breakdown of voting rights: (    )

Other (please specify) : (  X  )

Compliance with the Transparency Directive


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

Capital Group International, Inc.

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

.................



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

15 March 2007

6. Date on which issuer notified:

16 March 2007

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

5%

8. Notified details:

.................



A: Voting rights attached to shares


Class/type of shares if possible              Situation previous to the Triggering transaction
using the ISIN CODE
                                  Number of shares                   Number of voting Rights
 Ordinary Shares                  58,717,220                         58,717,220
American Depositary Receipt       23,499,200                         23,499,200

Resulting situation after the triggering transaction


Class/type of shares if      Number of shares        Number of voting rights           % of voting rights
possible using the ISIN CODE
                             Direct      Indirect    Direct       Indirect             Direct      Indirect

Ordinary Shares                          58,662,220               58,662,220                       3.8617%
American Depositary Receipt              23,208,206               23,208,206                       1.5278%



B: Financial Instruments

Resulting situation after the triggering transaction


Type of         Expiration Date      Exercise/Conversion       Number of voting rights     % of voting rights
financial                            Period/ Date              that may be acquired if the
instrument                                                     instrument is exercised/
                                                               converted.




N/A



Total (A+B)
Number of voting rights        % of voting rights

81,870,426                     5.378%



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

.................



Proxy Voting:



10. Name of the proxy holder:

.................



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:

Justin Hoskins - Assistant Secretary



15. Contact telephone number:

020 7304 5112


                      This information is provided by RNS
            The company news service from the London Stock Exchange