Rule 8.3 - Cambridge Antibody Technology Group Plc

    OZ Management, LLC



FORM 8.3

DEALINGS BY PERSONS WITH INTERESTS IN SECURITIES REPRESENTING 1% OR MORE

(Rule 8.3 of the City Code on Takeovers and Mergers)

1. KEY INFORMATION

Name of person dealing  (Note 1)          OZ Management, LLC
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Company dealt in                          Cambridge Antibody Technology Group Plc
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Class of relevant security to which the   Ordinary Shares  5p
 dealings being disclosed relate (Note 2)
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Date of dealing                           15 May 2006
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2. INTERESTS, SHORT POSITIONS AND RIGHTS TO SUBSCRIBE

(a) Interests and short positions (following dealing) in the class of relevant
security dealt in (Note 3)
                            Long                                Short
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                            Number            (%)               Number             (%)
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(1) Relevant securities
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(2) Derivatives (other than
 options)                   625,000           1.17%
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(3) Options and agreements
 to purchase/sell
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Total                       625,000           1.17%
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(b) Interests and short positions in relevant securities of the company, other
than the class dealt in (Note 3)
Class of relevant security: Long                                 Short
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                            Number           (%)                 Number             (%)
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(1) Relevant securities
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(2) Derivatives (other than
 options)
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(3) Options and agreements
 to purchase/sell
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Total
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(c) Rights to subscribe (Note 3)

Class of relevant security:               Details
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3. DEALINGS (Note 4)

(a) Purchases and sales

Purchase/sale                      Number of securities              Price per unit (Note 5)
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(b) Derivatives transactions (other than options)

Product name,       Long/short (Note 6)    Number of securities (Note 7)   Price per unit (Note 5)
e.g. CFD
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CFD                 Long                   625,000                         12. 9784GBP
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(c) Options transactions in respect of existing securities

(i) Writing, selling, purchasing or varying

Product name,      Writing,        Number of          Exercise  Type, e.g.   Expiry    Option money
e.g. call option    selling,        securities to     price      American,   date      paid/received
                    purchasing,     which the option             European               per unit (Note
                    varying etc.    relates (Note 7)             etc.                   5)
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(ii) Exercising

Product name, e.g. call option     Number of securities              Exercise price per unit (Note 5)
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(d) Other dealings (including new securities) (Note 4)

Nature of transaction (Note 8)     Details                           Price per unit (if applicable) (Note
                                                                      5)
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4. OTHER INFORMATION

Agreements, arrangements or understandings relating to options or derivatives

Full details of any agreement, arrangement or understanding between the person disclosing and any other
 person relating to the voting rights of any relevant securities under any option referred to on this
 form or relating to the voting rights or future acquisition or disposal of any relevant securities to
 which any derivative referred to on this form is referenced.  If none, this should be stated.
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None
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Is a Supplemental Form 8 attached? (Note 9) NO

Date of disclosure                                          16 May 2006
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Contact name                                                Joel M. Frank
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Telephone number                                            212-790-0160
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If a connected EFM, name of offeree/offeror with which
 connected
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If a connected EFM, state nature of connection (Note 10)
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Notes

The Notes on Form 8.3 can be viewed on the Takeover Panel's website at
www.thetakeoverpanel.org.uk