Preview | Commitment Letter |

MACQUARIE BANK LIMITED

Macquarie Infrastructure Company LLC

Macquarie Infrastructure Company Inc.

125 West 55^th Street

New York, New York 10019

Attention:

Francis T. Joyce

Chief Financial Officer

COMMITMENT LETTER

$330,000,000 AMENDED AND RESTATED REVOLVING CREDIT FACILITY

Ladies and Gentlemen:

You have advised us that Macquarie Infrastructure Company LLC (?Holdings?) and Macquarie Infrastructure Company Inc. (?Macquarie? and together with Holdings, collectively, the ?Company?) desire to increase to $330,000,000 the total aggregate amount of commitments under that certain Amended and Restated Revolving Credit Agreement, dated as of May 9, 2006 (the ?Existing Credit Facility?), by and among Macquarie, as borrower, Holdings, the Lenders and issuers party thereto and Citicorp North America, Inc., as administrative agent, which will require an additional amendment and restatement of the Existing Credit Facility (the ?Amended Facility?) on the terms and subject to the conditions set forth in the Amended Revolving Credit Facility Term Sheet attached hereto as Exhibit A (?Exhibit A? and, together with this letter, this ?Commitment Letter?). The Amended Facility shall consist of two tranches: (a) a tranche in an aggregate amount of US$300,000,000 (the ?Revolving Tranche?) and (b) a tranche in an aggregate principal amount of US$30,000,000 (the ?San Jose FBO Tranche?).

Subject to the terms and conditions described in this Commitment Letter, Macquarie Bank Limited (?Macquarie Bank? or ?we? or ?us?), is pleased to inform you of Macquarie Bank?s commitment to provide the Company the full principal amount of the San Jose FBO Tranche (which is in addition to Macquarie Bank?s existing commitment under the Existing Credit Facility), subject to the terms and conditions set forth in this Commitment Letter.

Section 1. Conditions Precedent.

The commitment and other obligations of Macquarie Bank hereunder are subject to:

(a) the preparation, execution and delivery of loan documentation with respect to the Amended Facility, including, without limitation, a further amended and restated credit agreement, security agreements, guaranties and other agreements, incorporating substantially the terms and conditions outlined in this Commitment Letter and reasonably satisfactory to Macquarie Bank (the ?Operative Documents?);

(b) the absence of any material adverse change in the operations, assets, financial condition or business of the Company and its subsidiaries, taken as a whole, since December 31, 2006;

(c) the accuracy and completeness on the effectiveness of the Amended Facility of all representations that the Company makes to Macquarie Bank and all information that the Company furnishes to Macquarie Bank;

(d) the Company?s compliance with the terms of this Commitment Letter, including, without limitation, the payment in full of all fees, expenses and other amounts payable under this Commitment Letter;

(e) the satisfaction by the Company of the other conditions precedent to the initial funding of the Amended Facility contained in Exhibit A; and

(f) the receipt of consents in respect of the transactions contemplated hereby duly executed and delivered by each of Citigroup North America, Inc., Credit Suisse, Merrill Lynch Capital Corporation and WestLB AG, New York Branch.