Exhibit 10.1

ISSUER CALL SPREAD

July 22, 2005

Cheniere Energy, Inc.

717 Texas Avenue, Suite 3100

Houston, Texas 77002

Attention: Don A. Turkleson, Chief Financial Officer

Credit Suisse First Boston International

One Cabot Square

London E 14 4QJ

England

Dear Sirs:

The purpose of this letter agreement (this “Confirmation”) is to confirm the terms and conditions of the Transaction entered into between Party A and Party B through the Agent on the Trade Date specified below (the “Transaction”). This Confirmation constitutes a “Confirmation” as referred to in the Agreement specified below.

This Confirmation shall supplement, form a part of, and be subject to an ISDA 1992 Master Agreement (Multicurrency – Cross Border) (the “Agreement”), as if, on the Trade Date, the parties hereto had executed that Agreement (without any Schedule thereto) and specified that (1) the Automatic Early Termination provisions contained in Section 6(a) of such Agreement would apply, (2) Second Method and Loss would apply, (3) US Dollars (“$”) were the Termination Currency, and (4) Section 5(a)(v) of the Agreement would not apply to either party.

The Agreement and each Confirmation thereunder will be governed by and construed in accordance with New York law and each party hereby submits to the jurisdiction of the courts of the State of New York and the United States District Court located in the Borough of Manhattan in New York City.

In this Confirmation, “Party A” means Credit Suisse First Boston International, “Party B” means Cheniere Energy, Inc., and “Agent” means Credit Suisse First Boston, acting through its New York branch and solely in its capacity as agent for Party A and Party B.

ISSUER CALL SPREAD

The particular terms relating to the option with the Strike Price set forth below (the “Upper Strike Option”) are as follows:

The general terms relating to both the Lower Strike Option and Upper Strike Option are as follows:

2

ISSUER CALL SPREAD

3

ISSUER CALL SPREAD

4

ISSUER CALL SPREAD

5

ISSUER CALL SPREAD

6

ISSUER CALL SPREAD

(i) Party A is entering into each Transaction in the ordinary course of its trade as, and is, a recognized U.K. bank as defined in Section 840A of the U.K. Income and Corporation Taxes Act of 1988.

(ii) Party A has been approved as a Withholding Foreign Partnership by the U.S. Internal Revenue Service.

(iii) Party A’s Withholding Foreign Partnership Employer Identification Number is 98-0330001.

(iv) Party A is a partnership that agrees to comply with any withholding obligation under Section 1446 of the Internal Revenue Code.

If Party A determines reasonably and in good faith that the number of Shares required to be delivered to Party B hereunder on any Cash Settlement Payment Date would exceed 9.9% of all outstanding Shares, then Party A may, by notice to Party B on or prior to such Cash Settlement Payment Date (a “Nominal Settlement Date”), elect to deliver the Shares comprising the related Cash Settlement Amount (in the case of Net Share Settlement) on two or more dates (each, a “Staggered Settlement Date”) as follows:

Notwithstanding anything herein to the contrary, Party A shall be entitled to deliver Shares to Party B from time to time prior to the date on which Party A would be obligated to deliver them to Party B pursuant to the Net Share Settlement terms set forth above, and Party B agrees to credit all such early deliveries against Party A’s obligations hereunder in the direct order in which such obligations arise. No

7

ISSUER CALL SPREAD

such early delivery of Shares will accelerate or otherwise affect any of Party B’s obligations to Party A hereunder. To the extent Party A receives or is entitled to receive any distribution or payment in respect of Shares by reason of Party A’s being a holder of record of such Shares on any date after the Nominal Settlement Date which Party A would have delivered to Party B on such Nominal Settlement Date but for the provisions of this Section 5, Party A shall deliver such distribution or payment to Party B at the time Party A delivers the related Shares to Party B in accordance with this Section 5, if such distribution or payment has already been received by Party A at such time, or within a reasonable period of time following Party A’s receipt of the distribution or payment, if such distribution or payment has not already been received by Party A at the time Party A delivers the related Shares to Party B in accordance with this Section 5.

Notwithstanding any other provision hereof, Party A may not exercise the Upper Strike Option, and Automatic Exercise shall not apply with respect thereto, if the exercise of the Upper Strike Option would cause Party A to become, directly or indirectly, the beneficial owner of more than 9.9 percent of the class of the Issuer’s equity securities that is comprised of the Shares for purposes of Section 13 of the Securities Exchange Act of 1934, as amended (in such case, an “Excess Share Owner”).

Party A shall provide prior notice to Party B, through the Agent, if the exercise of the Upper Strike Option would cause Party A to become directly or indirectly, an Excess Share Owner; provided that the failure of Party A to provide such notice shall not alter the effectiveness of the provisions set forth in the preceding sentence and any purported exercise in violation of such provisions shall be void and have no effect.

If Party A is not permitted to exercise the Upper Strike Option because such exercise would cause Party A to become, directly or indirectly, an Excess Share Owner and Party A thereafter disposes of Shares owned by it or any action is taken that would then permit Party A to exercise the Upper Strike Option without such exercise causing it to become, directly or indirectly, an Excess Share Owner, then Party A shall provide notice of the taking of such action to Party B, through the Agent, and the Upper Strike Option shall then become exercisable by Party A to the extent the Upper Strike Option is otherwise exercisable hereunder. In such event, the Expiration Date with respect to the Upper Strike Option shall be the date on which Party B receives such notice from Party A, and the related Settlement Date shall be as soon as reasonably practicable after receipt of such notice but no more than three (3) Business Days thereafter (but in no event shall the Settlement Date occur prior to the date on which it would have otherwise occurred but for the provisions of this Section 6; provided that the aggregate amounts of cash or Shares paid or delivered with respect to this Transaction shall not be affected by the provisions of this Section 6.

8

ISSUER CALL SPREAD

Credit Suisse First Boston, New York branch

Eleven Madison Avenue

New York, NY 10010-3629

For payments and deliveries:

Facsimile No.: (212) 325-8175

Telephone No.: (212) 325-8678 / (212) 325-3213

For all other communications:

Facsimile No.: (212) 325-8173

Telephone No.: (212) 325-8676 / (212) 538-5306 /

(212) 538-1193 / (212) 538-6886

9

ISSUER CALL SPREAD

(A) Party B will make available to Party A an effective registration statement (the “Registration Statement”) filed pursuant to Rule 415 under the Securities Act of 1933, as amended (the “Securities Act”), and such prospectuses as Party A may reasonably request to comply with the applicable prospectus delivery requirements (the “Prospectus”) for the resale by Party A of such number of Shares as Party A shall reasonably specify, such Registration Statement to be effective and Prospectus to be current until the date specified by Party A (the “Registration Period”); and

(B) Party B will make the following representation on each day during the Registration Period:

“Party B represents that the Registration Statement, at the time the same became effective, did not contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading; Party B represents the Prospectus (as the same may be supplemented from time to time) does not include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading.”;

(C) Party B will enter into a Registration Rights Agreement with Party A in form and substance reasonably acceptable to Party A, which agreement will contain among other things, customary representations and warranties and indemnification and other rights relating to the registration of a number of Shares.

(D)Party B shall promptly pay to Party A a $0.05 per Share fee with all Shares delivered in connection with subparagraph (ii) above.

In the event that Party B fails to comply with any of the conditions set forth above, Party B shall promptly pay in cash or Shares an additional amount to Party A equal to an amount reasonably determined by Party A to cover its costs and losses in connection with such failure.

10

ISSUER CALL SPREAD

Credit Suisse First Boston International is regulated by The Financial Services Authority and has entered into this transaction as principal. The time at which the above transaction was executed will be notified to Party B (through the Agent) on request.

11

ISSUER CALL SPREAD

Please confirm that the foregoing correctly sets forth the terms of your agreement by signing and returning this Confirmation.

Confirmed as of the date first written above:

CHENIERE ENERGY, INC. (Party B)

CREDIT SUISSE FIRST BOSTON INTERNATIONAL (Party A)

12

ISSUER CALL SPREAD

ANNEX I

Matters to be covered in Opinion of Counsel to the Issuer (the “Counterparty”)

1. The Counterparty is validly existing as a corporation in good standing under the laws of the State of Delaware.

2. The Counterparty has the requisite corporate power and authority to enter into the Issuer Call Spread (for purposes of this Annex 1, the “Agreement”) and to carry out the Transactions contemplated thereby.

3. The execution and delivery by the Counterparty of the Agreement, and the performance by the Counterparty of its obligations under the Agreement, have been duly authorized by all necessary corporate action on the part of the Counterparty.

4. The Agreement have been duly authorized, executed and delivered by the Counterparty and constitute the legal, valid and binding obligations of the Counterparty, enforceable against the Counterparty in accordance with their respective terms.

5. Other than as set forth in, or incorporated by reference into, the Final Offering Circular of the Counterparty relating to the offering of the Reference Notes, in the United States, there is not pending of threatened any action, suit, proceeding, inquiry or investigation, to which the Counterparty or any subsidiary is a party, or to which the property of the Counterparty or any subsidiary is subject, before or brought by any U.S. court or governmental agency or body, which could reasonably be expected to materially and adversely affect the properties or assets thereof or the consummation of the Transactions or the performance by the Counterparty of its obligations thereunder.

6. No consent, approval or authorization of, or registration, filing or declaration with, any governmental or public body or authority is required in connection with the execution, delivery or performance by the Counterparty of the Agreement.

7. The execution, delivery and performance by the Counterparty of the Agreement and compliance by the Counterparty with the terms and provisions thereof will not, whether with or without the giving of notice or lapse of time or both, result in a breach or violation of any of the terms and provisions of, or constitute a default under, (A) any indenture, mortgage, deed of trust, loan, purchase or credit agreement, lease, corporate charter or by-laws, or any other agreement or instrument to which the Counterparty or any subsidiary is bound or by which the Counterparty or any subsidiary or any of their respective properties may be bound or affected, or (B) any Delaware or federal law, statute, rule, regulation or order or any judgment, order, writ or decree of any governmental agency or body or any court having jurisdiction over the Counterparty or any of its properties.

8. Neither the Counterparty nor any subsidiary is an “investment company” or a company “controlled” by an “investment company”, in each case within the meanings ascribed to such terms in the Investment Company Act of 1940, as amended, nor is the Counterparty or any subsidiary subject to regulation under said Act.

13

ISSUER CALL SPREAD

Annex II

Notice of Adjustment

This Notice of Adjustment (“Notice of Adjustment”) dated as of [                    ], 2005 is entered into pursuant to the terms of the Confirmation entered into between Credit Suisse First Boston International (“Party A”) and Cheniere Energy, Inc. (“Party B”), through Credit Suisse First Boston, acting through its New York branch and solely in its capacity as agent for Party A and Party B (the “Agent”) on July 22, 2005. Capitalized terms used herein without definition shall have the same meanings given to such terms in the Confirmation.

The terms of the Transaction to which this Notice of Adjustment relates are as follows:

[REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]

14

ISSUER CALL SPREAD

Please confirm that the foregoing correctly sets forth the terms of your agreement by signing and returning this Notice of Adjustment.

Confirmed as of the date first written above:

CHENIERE ENERGY, INC. (Party B)

CREDIT SUISSE FIRST BOSTON INTERNATIONAL (Party A)

15