CSL Ltd. — M&A Activity 2006

Sep 11, 2006

576 Swan Street Richmond Victoria Australia 3121 Telephone (61 3) 9208 4000

Facsimile (61 3) 9208 4350

www.zenyth.com.au

Tuesday, 12 September 2006

ASX Announcement for immediate release

CSL and Zenyth merger proposal update

On 17 July 2006, Zenyth Therapeutics Limited (Zenyth) and CSL Limited (CSL) jointly announced a proposal under which CSL would acquire 100% of the issued shares in Zenyth.

The proposed acquisition will be implemented by way of a scheme of arrangement between Zenyth and its shareholders under which all Zenyth shares will be transferred to CSL for a cash payment of \$0.82 per share (Share Scheme). In addition to the Share Scheme, the following two ancillary transactions are proposed:

• a pro-rata capital return by Zenyth to its shareholders of all of the shares that Zenyth holds in Avexa Limited (Avexa) (Special Distribution). If approved, the Special Distribution will result in eligible Zenyth Shareholders receiving, in addition to the cash payment from CSL of \$0.82 per Zenyth share, approximately 1 Avexa share for every 6 Zenyth shares they hold; and
• a scheme of arrangement between Zenyth and its optionholders under which all Zenyth options outstanding as at the option scheme record date will be cancelled and optionholders will receive cash consideration of between \$0.0100 and \$0.5196 per Zenyth Option, depending on the terms of issue of the relevant Zenyth Options (Option Scheme).

The Share Scheme, Special Distribution and Option Scheme are collectively referred to below as the CSL Acquisition Proposal.

Zenyth advises that the Supreme Court of Victoria has today made orders under section 411(1) of the Corporations Act 2001 (Cth) directing Zenyth to convene meetings of its shareholders and optionholders to consider and vote on the proposed Share Scheme and the proposed Option Scheme.

Three meetings of Zenyth security holders will be held on Monday, 23 October 2006 in relation to the CSL Acquisition Proposal:

• The first meeting is convened by the orders made today by the Supreme Court of Victoria to consider and vote on the proposed Share Scheme.
• The second meeting is a General Meeting convened by Zenyth to consider and vote on the Special Distribution.
• The third meeting is convened by the orders made today by the Supreme Court of Victoria to consider and vote on the proposed Option Scheme.

The three meetings will be held at the offices of Computershare, 452 Johnston Street, Abbotsford, Victoria, with the Share Scheme meeting commencing at 2.00 pm (Australian Eastern Standard Time). The General Meeting will commence at 2.30 pm (Australian Eastern Standard Time) or immediately following the conclusion or adjournment of the Share Scheme meeting to be held on the same day, whichever time is later. The Option Scheme meeting will commence at 3.00 pm (Australian Eastern Standard Time) or immediately following the conclusion or adjournment of the General Meeting to be held on the same day, whichever time is later.

Zenyth's Directors unanimously support the CSL Acquisition Proposal and recommend that, in the absence of a more favourable proposal:

• Zenyth Shareholders vote in favour of the Share Scheme and Special Distribution; and
• Zenyth Optionholders vote in favour of the Option Scheme.

In the absence of a more favourable proposal, each Director intends to vote in favour of the Share Scheme and the Special Distribution in respect of all Zenyth shares held by him or in which he otherwise has a relevant interest. The Company's Chief Executive Officer, Dr Nash, being the only Director holding Zenyth Options, intends to vote in favour of the Option Scheme in respect of all unexercised Zenyth options held by him, in the absence of a more favourable proposal from another party.

The notices convening the three meetings referred to above will be included in an explanatory booklet to be despatched to Zenyth security holders shortly. The explanatory booklet contains all relevant information in relation to the CSL Acquisition Proposal, including the manner in which it will be considered and, if approved, implemented, and other information material to the decision of Zenyth security holders whether to approve the CSL Acquisition Proposal.

The explanatory booklet will also contain an independent expert's report by Deloitte Corporate Finance. The independent expert has concluded that, in the absence of a more favourable proposal from another party:

• the Share Scheme and the Special Distribution are in the best interests of Zenyth Shareholders; and
• the Option Scheme is on balance in the best interests of Zenyth Optionholders as a whole.

If all of the conditions and approvals required for the CSL Acquisition Proposal are satisfied or waived (as applicable), Zenyth will seek Court approval for the Schemes on or about 31 October 2006 and expects that the CSL Acquisition Proposal will be fully implemented on or about 17 November 2006.

Robyn M Fry General Counsel and Company Secretary Zenyth Therapeutics Limited

For further information contact: Mr Ian Davis Chairman +61 3 8608 2962