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                                                                   Exhibit 10.27

                      MACQUARIE INFRASTRUCTURE COMPANY LLC

                                     - AND -

                               BALFOUR BEATTY PLC

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                            PARENT COMPANY GUARANTEE

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THIS GUARANTEE is made the 22nd day of December, 2004

BETWEEN:

(1)  MACQUARIE INFRASTRUCTURE COMPANY LLC, whose principal executive office is
     at 600 Fifth avenue, 21st floor, 10020 NY, USA (formerly Macquarie
     Infrastructure Assets LLC) (hereinafter called "MICL" or the "GUARANTOR");
     and

(2)  BALFOUR BEATTY PLC, whose registered office is at 130 Wilton Road, London
     SW1W 1LQ (hereinafter called "BB").

WHEREAS:

(A)  Under a parent company guarantee dated 26 March 1996, as amended and
     restated on 30 April 2003, between BB and Macquarie European Infrastructure
     Plc ("MEIP") (the "Parent Company Guarantee"), MEIP agreed to guarantee (1)
     the due performance by Macquarie Yorkshire Limited ("MYL") of a
     shareholders' agreement dated 26 March 1996, as amended and restated on 30
     April 2003, between MYL, BB, Yorkshire Link (Holdings) Limited ("YLHL"),
     Yorkshire Link Limited ("YLL") and MEIP (the "Shareholders' Agreement") and
     (2) the due performance by Macquarie Infrastructure (UK) Limited ("MIUK")
     of a technical services agreement dated 26 March 1996 between YLL, MIUK and
     BB (the "Technical Services Agreement") and a secondment agreement dated 26
     March 1996, as amended and restated on 30 April 2003, between YLL, BB and
     MIUK (the "Secondment Agreement").

(B)  On 10 March 2004 the Technical Services Agreement was terminated.

(C)  YLL changed its name to Connect M1-A1 Limited on 2 June 2004 ("Connect");
     YLHL changed its name to Connect M1-A1 Holdings Limited ("Connect
     Holdings") on 2 June 2004.

(D)  Pursuant to a share purchase agreement entered into between MEIP and MICL
     on or around the date hereof (the "Share Purchase Agreement"), MEIP will
     sell and MICL will purchase the 5,000,000 ordinary shares owned by MEIP in
     MYL (the "Transaction").

(E)  Prior to Completion (as defined in the Share Purchase Agreement), MICL
     intends to notify MEIP that it wishes to nominate Macquarie Yorkshire LLC
     ("MY LLC") as the transferee of the Shares (as defined in the Share
     Purchase Agreement) pursuant to paragraph 1 of Schedule 5 of the Share
     Purchase Agreement.

(F)  As a result of the Transaction MEIP wished to be released and discharged
     from the Shareholders' Agreement and the parties agreed to the novation of
     the Shareholders' Agreement. BB, MEIP, MYL, Connect, Connect Holdings, MY
     LLC and MICL entered into a deed of novation of the Shareholders' Agreement
     on or around the date hereof (the "Shareholders' Agreement Novation")
     pursuant to which the Shareholders' Agreement was terminated and replaced
     by a replacement shareholders' agreement between BB, MY LLC, MYL, Connect
     and Connect Holdings (the "Replacement Shareholders' Agreement").

(G)  As a result of the Transaction MIUK wished to be released and discharged
     from the Secondment Agreement and the parties agreed to the novation of the
     Secondment Agreement. BB, MIUK, Connect, MYL and MICL entered into a deed
     of novation of the Secondment Agreement on or around the date hereof (the
     "Secondment Agreement Novation") pursuant to which the Secondment Agreement
     was terminated and replaced by a replacement secondment agreement between
     BB, MYL and Connect (the "Replacement Secondment Agreement").


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(H)  On or around the date hereof, BB entered into a deed of release with MEIP
     under which MEIP was released from its obligations under the Parent Company
     Guarantee.

(I)  Pursuant to the Replacement Shareholders' Agreement, the parties have
     agreed to enter into this guarantee and the Guarantor has agreed to
     guarantee to BB (1) the due performance by MY LLC of its obligations under
     the Shareholders' Agreement Novation and (2) the due performance by MYL of
     its obligations under the Replacement Shareholders' Agreement, the
     Secondment Agreement Novation, and the Replacement Secondment Agreement
     (together the "Relevant Contracts").

NOW THIS DEED WITNESSES as follows:

1.   The Guarantor hereby unconditionally and irrevocably guarantees to and
     covenants with BB that:

     (a)  MYL and MY LLC will well and truly perform and observe all
          obligations, terms, provisions, conditions and stipulations mentioned
          or described in the Relevant Contracts to which they are a party or to
          be implied therefrom on its/their part to be so performed and observed
          according to the true purport, intent and meaning hereof; and

     (b)  if for any reason whatsoever and in any way MYL or MY LLC shall fail
          to perform the same, then the Guarantor shall, upon receipt of a
          notice in writing from BB, take over from MYL or MY LLC (as
          appropriate) and shall forthwith perform and observe or cause to be
          performed and observed such obligations, terms, provisions, conditions
          and stipulations as aforesaid so far as and to the extent MYL or MY
          LLC (as appropriate) was liable to perform and observe them and shall
          to the same extent be responsible to BB as principal and not merely as
          surety for MYL or MY LLC (as appropriate) for the payment by them of
          all sums of money, losses, damages, costs, charges and expenses that
          may become due or payable to BB by reason or in consequence of the
          acts or defaults of MYL or MY LLC (as appropriate) in the performance
          or observance of the Relevant Contracts.

     Provided that under no circumstance whatsoever shall the liabilities of the
     Guarantor, MYL and MY LLC pursuant to this Guarantee and the Relevant
     Contracts either individually or when aggregated together hereunder exceed
     the liability which MYL or MY LLC has under the Relevant Contracts.

     Such notices as aforesaid shall be signed by Christopher R. O'N. Pearson,
     Company Secretary of BB, a copy of whose signature is attached hereto as
     Schedule 1 (or his respective successor in post whose name and specimen
     signature must be advised to the Guarantor and authenticated by the Company
     Secretary of BB for the time being).


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2.   Notices in writing of such failure to perform as aforesaid may from time to
     time be sent by BB to the Guarantor at 600 Fifth Avenue, 21st Floor, 10020
     NY, USA by either registered mail (and shall be regarded as being received
     personally by the Guarantor five days after their posting by BB) or
     delivered personally to the Guarantor at its aforementioned address and
     regarded as delivered at the time of delivery. Each notice of such failure
     to perform shall specify the failure.

3.   As between BB and the Guarantor notices in writing of default as aforesaid
     shall be conclusive evidence of MYL's or MY LLC's default in performance or
     observance of any of their outstanding obligations under the Relevant
     Contracts.

4.   The obligations of the Guarantor hereunder are primary and not by way of
     surety only and the Guarantor shall not be entitled as against MYL or MY
     LLC to any right of set off or counterclaim whatsoever and howsoever
     arising.

5.   This Guarantee is irrevocable and shall not be assigned by either party.

6.   The Guarantor shall not in any way be released or discharged or otherwise
     absolved of liability hereunder by reason of any of the following (whether
     or not the Guarantor has notice thereof):

     (a)  any alteration amendment or variation in the terms of the Relevant
          Contracts;

     (b)  any indulgence forgiveness or forbearance shown by BB towards MYL or
          MY LLC whether as to payment or time for payment of any arrangement
          entered into or composition accepted by BB or otherwise modifying (by
          operation of law or otherwise) the rights and remedies of BB under the
          Relevant Contracts or hereunder with regard to payment or time for
          payment or otherwise changing the obligations of either party under
          the Relevant Contracts;

     (c)  any action lawfully taken by BB to determine the Relevant Contracts;

     (d)  any change in the relationship between the Guarantor and MYL or MY
          LLC;

     (e)  any disability or incapacity or change in status or constitution of
          MYL, MY LLC or the Guarantor;

     (f)  the liquidation or dissolution or insolvency of any of the parties
          referred to herein or any receivership administration moratorium
          composition of creditors claims or other analogous event effecting
          such parties or any of their property or assets; and

     (g)  any failure or delay to assert any of BB's rights under this
          Guarantee.


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7.   Any waiver by BB of the terms of this Guarantee or any consent or approval
     given by BB shall only be effective if given in writing and then only for
     the purpose and upon the terms and conditions if any on which it is given.

8.   If at any time one or more of the provisions of this Guarantee is or
     becomes invalid or otherwise unenforceable in any respect neither the
     validity or enforceability of the remaining provisions of this Guarantee
     nor the validity or enforceability of such provision under the law shall in
     any way be affected or impaired as a result.

9.   Terms and conditions used in this Guarantee shall bear the same meaning as
     in the Replacement Shareholders' Agreement where such have a specific
     meaning ascribed to them.

10.  The Guarantor shall at all times maintain an agent for service of process
     and any other documents in proceedings in England or any other proceedings
     in connection with this guarantee. Such agent shall be MYL of Level 29 and
     30, 1 Ropemaker Street, London EC2Y 9HD and any judgment or other notice of
     legal process shall be sufficiently served on the Guarantor if delivered to
     such agent at its address for the time being. The Guarantor agrees to
     inform BB in writing of any change of address of such process agent within
     28 days of such change. If such process agent ceases to be able to act as
     such or to have an address in England, the Guarantor irrevocably agrees to
     appoint a new process agent in England and to deliver to BB within 14 days
     a copy of a written acceptance of appointment by the process agent.

11.  This Deed shall be governed by and construed in accordance with the laws of
     England and shall be submitted to the exclusive jurisdiction of the English
     Courts.

In witness whereof the Guarantor and BB have executed this document as a Deed
the day and year first before written.

MACQUARIE INFRASTRUCTURE COMPANY LLC

EXECUTED and DELIVERED by              )    /s/ Peter Stokes
                                       )    ------------------------------------
                                       )    Name(s): Peter Stokes
                                       )    Authorised Signatory/Signatories
as authorised signatory on behalf of
Macquarie Infrastructure Company
LLC and thereby executed by it as
a Deed

BALFOUR BEATTY PLC

EXECUTED as a Deed by Balfour          )    /s/ A. L. P. Rabin
Beatty PLC acting by                   )    ------------------------------------
                                       )    Name: A. L. P. Rabin
                                       )    Director
and                                    )

                                            /s/ C.R. O'N Pearson
                                            ------------------------------------
                                            Name: C.R. O'N Pearson
                                            Secretary


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                                   SCHEDULE 1

          SPECIMEN SIGNATURE OF COMPANY SECRETARY OF BALFOUR BEATTY PLC

The following signature is the specimen signature of the Company Secretary of
Balfour Beatty plc who is authorised to issue notices under paragraph 1(b) of
the Parent Company Guarantee:


Name: C.R. O'N Pearson                      Signature: /s/ C.R. O'N Pearson


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