Posting of Scheme Document

NOT FOR RELEASE, PUBLICATION OR DISTRIBUTION, IN WHOLE OR IN PART, IN, INTO OR FROM ANY JURISDICTION WHERE TO DO SO WOULD CONSTITUTE A VIOLATION OF THE RELEVANT LAWS OF SUCH JURISDICTION.

FOR IMMEDIATE RELEASE

14 December 2011

Recommended Cash Acquisition

by

SDL plc

of

Alterian plc

Posting of Scheme Document

On 2 December 2011, the Alterian Independent Directors announced that they had reached agreement on the terms of the cash Acquisition to acquire the whole of the issued and to be issued share capital of Alterian plc ("Alterian" or the "Company") by SDL plc ("SDL"). The Acquisition is to be implemented by way of a Court-approved scheme of arrangement (the "Scheme").

Accordingly, Alterian now announces that a scheme document in relation to the Scheme (the "Scheme Document") is being posted to Alterian Shareholders today, 14 December 2011.

A detailed timetable of events for the Scheme is set out in the appendix to this announcement. These dates are indicative only and will depend, amongst other things, on the date on which the Court sanctions the Scheme and the associated Capital Reduction. If the expected dates change, the Company will give notice of the changes in an announcement through a Regulatory Information Service.

A copy of the Scheme Document will shortly be available for inspection at the Financial Services Authority's National Storage Mechanism which can be accessed at www.hemscott.com/nsm.do.

Words and expressions defined in the Scheme Document shall, unless the context provides otherwise, have the same meanings in this announcement.

Enquiries:

Canaccord Genuity Limited, which is authorised and regulated in the United Kingdom by the FSA, is acting exclusively for Alterian and no one else in connection with the Acquisition and will not be responsible to anyone other than Alterian for providing the protections afforded to clients of Canaccord Genuity Limited nor for providing advice in relation to the Acquisition or any other matter or arrangement referred to in this announcement.

Investec Bank plc, which is authorised and regulated in the United Kingdom by the FSA, is acting exclusively for SDL and no one else in connection with the Acquisition and will not be responsible to anyone other than SDL for providing the protections afforded to clients of Investec Bank plc nor for providing advice in relation to the Acquisition or any other matter or arrangement referred to in this announcement.

Disclosure requirements of the Code

Under Rule 8.3(a) of the Code, any person who is interested in 1% or more of any class of relevant securities of an offeree company or of any paper offeror (being any offeror other than an offeror in respect of which it has been announced that its offer is, or is likely to be, solely in cash) must make an Opening Position Disclosure following the commencement of the offer period and, if later, following the announcement in which any paper offeror is first identified. An Opening Position Disclosure must contain details of the person's interests and short positions in, and rights to subscribe for, any relevant securities of each of (i) the offeree company and (ii) any paper offeror(s). An Opening Position Disclosure by a person to whom Rule 8.3(a) applies must be made by no later than 3.30 p.m. (London time) on the 10th business day following the commencement of the offer period and, if appropriate, by no later than 3.30 p.m. (London time) on the 10th business day following the announcement in which any paper offeror is first identified. Relevant persons who deal in the relevant securities of the offeree company or of a paper offeror prior to the deadline for making an Opening Position Disclosure must instead make a Dealing Disclosure.

Under Rule 8.3(b) of the Code, any person who is, or becomes, interested in 1% or more of any class of relevant securities of the offeree company or of any paper offeror must make a Dealing Disclosure if the person deals in any relevant securities of the offeree company or of any paper offeror. A Dealing Disclosure must contain details of the dealing concerned and of the person's interests and short positions in, and rights to subscribe for, any relevant securities of each of (i) the offeree company and (ii) any paper offeror, save to the extent that these details have previously been disclosed under Rule 8. A Dealing Disclosure by a person to whom Rule 8.3(b) applies must be made by no later than 3.30 p.m. (London time) on the business day following the date of the relevant dealing.

If two or more persons act together pursuant to an agreement or understanding, whether formal or informal, to acquire or control an interest in relevant securities of an offeree company or a paper offeror, they will be deemed to be a single person for the purpose of Rule 8.3.

Opening Position Disclosures must also be made by the offeree company and by any offeror and Dealing Disclosures must also be made by the offeree company, by any offeror and by any persons acting in concert with any of them (see Rules 8.1, 8.2 and 8.4).

Details of the offeree and offeror companies in respect of whose relevant securities Opening Position Disclosures and Dealing Disclosures must be made can be found in the Disclosure Table on the Takeover Panel's website at www.thetakeoverpanel.org.uk, including details of the number of relevant securities in issue, when the offer period commenced and when any offeror was first identified. If you are in any doubt as to whether you are required to make an Opening Position Disclosure or a Dealing Disclosure, you should contact the Panel's Market Surveillance Unit on +44 (0)20 7638 0129.

Publication on websites

Copies of this announcement and the Scheme Document are available free of charge, subject to certain restrictions relating to persons resident in Restricted Jurisdictions, at Alterian's and SDL's websites www.alterian.com and www.sdl.com respectively, up to and including the Scheme Effective Date.

For the avoidance of doubt, the content of the websites referred to above is not incorporated into and does not form part of this announcement.

APPENDIX

EXPECTED TIMETABLE OF PRINCIPAL EVENTS

The following indicative timetable sets out expected dates for the implementation of the Scheme.

All references in this announcement to times are to times in London (unless otherwise stated).

The Court Meeting and the General Meeting will each be held at the offices of Osborne Clarke, One London Wall, London EC2Y 5EB.

1 It is requested that the WHITE Form of Proxy for the Court Meeting be lodged before 10.00 a.m. on 4 January 2012, or, if the Court Meeting is adjourned, not later than 48 hours before the time fixed for the holding of the adjourned meeting. WHITE Forms of Proxy not so lodged may be handed to the Chairman of the Court Meeting before the taking of the poll at the Court Meeting.

2 The BLUE Form of Proxy for the General Meeting must be lodged before 10.15 a.m. on 4 January 2012 in order for it to be valid, or, if the General Meeting is adjourned, not later than 48 hours before the time fixed for the holding of the adjourned meeting. The BLUE Form of Proxy cannot be handed to the Chairman of the General Meeting at that meeting.

3 If either the Court Meeting or the General Meeting is adjourned, the Voting Record Time for the adjourned meeting will be 6.00 p.m. on the day which is two days before the adjourned meeting.

4 Or as soon thereafter as the Court Meeting shall have been concluded or adjourned.

5 These times and dates are indicative only and will depend, among other things, on the date on which the Conditions are either satisfied, or (if capable of waiver) waived, and the dates upon which the Court sanctions the Scheme and confirms the associated Capital Reduction. It will also depend on whether the Court Order(s) sanctioning the Scheme and confirming the Capital Reduction and, in relation to the Capital Reduction, the statement of capital are delivered to the Registrar of Companies, and if required by the Court, when the Capital Reduction Court Order is registered. Alterian will give notice of the change(s) by issuing an announcement through a Regulatory Information Service and, if required by the Panel, post notice of the change(s) to Alterian Shareholders and, for information only, to participants in the Alterian Share Schemes.