Posting of Offer Document

NOT FOR RELEASE, PUBLICATION OR DISTRIBUTION (IN WHOLE OR IN PART), DIRECTLY OR INDIRECTLY, IN, INTO OR FROM THE UNITED STATES, CANADA, AUSTRALIA OR JAPAN OR ANY OTHER JURISDICTION WHERE TO DO SO WOULD CONSTITUTE A VIOLATION OF THE RELEVANT LAWS OF SUCH JURISDICTION

FOR IMMEDIATE RELEASE

17 September 2015

RECOMMENDED CASH OFFER

by

BARBICAN BIDCO LIMITED

(a company controlled by Balfour Beatty Infrastructure Partners, L.P.)

for

ALKANE ENERGY PLC

Posting of Offer Document

Further to the announcement of 16 September 2015 in which the Boards of Barbican Bidco Limited ("Barbican") and Alkane Energy Plc ("Alkane") announced that they had reached agreement on the terms of a recommended cash offer to be made by Barbican (a company controlled by Balfour Beatty Infrastructure Partners, L.P. ("BBIP")) for the entire issued and to be issued share capital of Alkane (the "Offer"), Barbican is today publishing and posting to Alkane Shareholders a document (the "Offer Document"), containing the full terms and conditions of the Offer, together with the relevant Form of Acceptance. It is also being sent, for information purposes only, to persons with information rights and to participants in the Alkane Share Incentive Schemes.

The First Closing Date of the Offer is 8 October 2015. To accept the Offer in respect of Alkane Shares held in certificated form (that is, not in CREST), shareholders should complete and return the Form of Acceptance so as to be received by no later than 1.00 p.m. (London time) on 8 October 2015 in accordance with the procedure set out in the Offer Document. To accept the Offer in respect of shares held in uncertificated form (that is, shares held in CREST), shareholders should ensure than an Electronic Acceptance is made and that settlement occurs no later than 1.00 p.m. (London time) on 8 October 2015 in accordance with the procedure set out in the Offer Document.

Unless otherwise defined in this announcement, capitalised words and phrases used in this announcement shall have the same meanings given to them in the Offer Document.

Copies of the Offer Document are available for inspection on Barbican's website, hosted by BBIP LLP, at www.bbip.com, until the end of the Offer Period.

Further information

This announcement is for information only and is not intended to and does not constitute, or form part of, any offer to sell or invitation to purchase or subscribe for any securities, or any solicitation of any vote or approval in any jurisdiction pursuant to the Offer or otherwise. The Offer will be effected solely through the Offer Document, which, together with the Form of Acceptance (in relation to Alkane Shareholders holding shares in certificated form only) will contain the full details, terms and conditions of the Offer, including the details of how to accept the Offer. This announcement has been issued by and is the sole responsibility of Barbican.

Any decision regarding the Offer should be made only on the basis of information referred to in the Offer Document and the Form of Acceptance which Barbican is despatching today to Alkane Shareholders, persons with information rights and, for information only, to participants in the Alkane Share Incentive Schemes.

Please be aware that addresses, electronic addresses and certain other information provided by Alkane Shareholders, persons with information rights and other relevant persons in connection with the receipt of communications from Alkane may be provided to Barbican during the Offer Period as required under Section 4 of Appendix 4 to the Takeover Code.

Investec, which is authorised by the Prudential Regulation Authority and regulated in the United Kingdom by the Financial Conduct Authority and the Prudential Regulation Authority, is acting exclusively for Barbican and BBIP and no one else in connection with the Offer and will not be responsible to anyone other than Barbican and BBIP for providing the protections afforded to its clients or for providing advice in relation to the Offer or any other matters referred to herein.

Altium, which is authorised and regulated in the United Kingdom by the Financial Conduct Authority, is acting exclusively for Alkane and no one else in connection with the Offer and this announcement and will not be responsible to anyone other than Alkane for providing the protections afforded to clients of Altium nor for providing advice in connection with the Offer or this announcement or any matter referred to herein.

Liberum, which is authorised and regulated in the United Kingdom by the Financial Conduct Authority, is acting exclusively for Alkane and no one else in connection with the Offer and this announcement and will not be responsible to anyone other than Alkane for providing the protections afforded to clients of Liberum nor for providing advice in connection with the Offer or this announcement or any matter referred to herein.

Overseas Shareholders

The Offer will not be made, directly or indirectly, in or into, or by use of the mails, or by any means or instrumentality (including, without limitation, by means of telephone, facsimile, telex, internet or other forms of electronic communication) of interstate or foreign commerce of, or any facilities of a securities exchange of, the United States, Canada, Australia or Japan, and the Offer will not be capable of acceptance by any such use, means, instrumentality or facility or from within the United States, Canada, Australia or Japan. Accordingly, copies of this announcement and any other related document will not be, and must not be, directly or indirectly, mailed or otherwise distributed or sent in or into the United States, Canada, Australia or Japan and persons receiving such documents (including custodians, nominees and trustees) must not distribute or send them in, into or from such jurisdictions as doing so may violate the laws of such jurisdictions and may make invalid any purported acceptance of the Offer by persons in any such jurisdiction.

This announcement has been prepared for the purpose of complying with English law, the AIM Rules, the rules of the London Stock Exchange and the Takeover Code, and the information disclosed may not be the same as that which would have been disclosed if this announcement had been prepared in accordance with the laws of jurisdictions outside the UK.

Disclosure requirements of the Takeover Code (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 securities exchange 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 securities exchange 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 securities exchange 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 pm (London time) on the 10th business day following the commencement of the offer period and, if appropriate, by no later than 3.30 pm (London time) on the 10th business day following the announcement in which any securities exchange offeror is first identified. Relevant persons who deal in the relevant securities of the offeree company or of a securities exchange 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 securities exchange offeror must make a Dealing Disclosure if the person deals in any relevant securities of the offeree company or of any securities exchange 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 securities exchange offeror(s), 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 pm (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 securities exchange 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. You should contact the Panel's Market Surveillance Unit on +44 (0)20 7638 0129 if you are in any doubt as to whether you are required to make an Opening Position Disclosure or a Dealing Disclosure.

Cautionary note regarding forward-looking statements

This announcement contains certain forward-looking statements with respect to the financial condition, results of operations and business of the Alkane Group and certain plans and objectives of the boards of directors of Alkane and Barbican and of BBIP. These forward-looking statements can be identified by the fact that they do not relate only to historical or current facts. Forward-looking statements often use words such as "anticipate", "target", "expect", "estimate", "intend", "plan", "goal", "believe", "will", "may", "should", "would", "could" or other words of similar meaning. These statements are based on assumptions and assessments made by the boards of directors of Alkane and Barbican and of BBIP in light of their experience and their perception of historical trends, current conditions, expected future developments and other factors they believe appropriate. By their nature, forward-looking statements involve risk and uncertainty, and the factors described in the context of such forward-looking statements in this announcement could cause actual results and developments to differ materially from those expressed in or implied by such forward-looking statements. Should one or more of these risks or uncertainties materialise, or should underlying assumptions prove incorrect, actual results may vary materially from those described in this announcement. Alkane, Barbican and BBIP assume no obligation to update or correct the information contained in this announcement, whether as a result of new information, future events or otherwise, except to the extent legally required.

The statements contained in this announcement are made as at the date of this announcement, unless some other time is specified in relation to them, and service of this announcement shall not give rise to any implication that there has been no change in the facts set out in this announcement since such date. Nothing contained in this announcement shall be deemed to be a forecast, projection or estimate of the future financial performance of Alkane except where expressly stated.

Publication of this announcement

A copy of this announcement and the display documents required to be published pursuant to Rule 26.1 of the Takeover Code will be available, subject to certain restrictions relating to persons resident in the United States, Canada, Australia and Japan, on www.bbip.com and on www.alkane.co.uk by no later than 12 noon on 18 September 2015.

Neither the content of Alkane's nor BBIP LLP's websites nor the content of any websites accessible from hyperlinks on such websites (or any other websites) are incorporated into, or form part of, this announcement nor, unless previously published by means of a recognised information service, should any such content be relied upon in reaching a decision regarding the matters referred to in this announcement.

The Offer is subject to the provisions of the Takeover Code.