Exhibit 10.1

PARENT COMPANY PAYMENT GUARANTY

THIS PAYMENT GUARANTY (this “Guaranty”), dated as of December 11, 2006, is by
Mirant Corporation, a Delaware corporation (“Seller Guarantor”), to and in favor
of Tokyo Crimson Energy Holdings Corporation, a company existing and organized
under the laws of the Cayman Islands (“Buyer”).

Recitals:

A.                                   Mirant Asia-Pacific Ventures, Inc., a
Delaware corporation, and Mirant Asia-Pacific Holdings, Inc., a Delaware
corporation (together, “Sellers”), are affiliates of Seller Guarantor.

B.                                     Under the Stock and Note Purchase
Agreement, dated as of the date hereof (as it may be amended, modified or
supplemented from time to time in accordance with its terms, the “Agreement”),
by and between Sellers, Mirant Sweden International AB (publ), a public limited
company organized under the laws of Sweden (“Mirant Sweden”), and Buyer, Sellers
will sell, convey, assign, transfer and deliver to Buyer, and Buyer will
purchase and accept from Seller, all of the Ordinary Shares (as defined in the
Agreement), and Mirant Sweden will sell, and Buyer will purchase, the
Intercompany Notes (as defined in the Agreement).

C.                                     Seller Guarantor will derive a
substantial benefit from the sale by Sellers of the Ordinary Shares.

D.                                    In connection with the execution of the
Agreement, the parties hereto wish to enter into this Guaranty pursuant to which
Seller Guarantor agrees, subject to the terms, conditions and limitations stated
herein, to provide a guaranty of the payment obligations of Sellers under the
Agreement.

E.                                      Capitalized terms used in this Guaranty,
but not defined herein, shall have the meanings given to such terms in the
Agreement.

NOW, THEREFORE, Seller Guarantor covenants and agrees with Buyer as follows:

1.                                       Guaranty.  Seller Guarantor hereby
irrevocably, absolutely and unconditionally guarantees the full and timely
satisfaction by Sellers of all of Sellers’ payment obligations to Buyer under
the Agreement and the other documents executed and delivered by Sellers to Buyer
in connection with the Closing of the transactions contemplated thereunder
(collectively, and together with the Agreement, the “Closing Documents”). 
Seller Guarantor agrees that, in the event that Sellers fail to satisfy any of
their payment obligations to Buyer under the Closing Documents, as each may from
time to time be amended (the “Guaranteed Obligations”), then Seller Guarantor
will pay such Guaranteed Obligations in the place and stead of Sellers.  In the
event Sellers become obligated to pay any Guaranteed Obligations and fail to
timely pay such obligations in

--------------------------------------------------------------------------------

accordance with the terms of the Closing Documents, then Buyer may provide
written notice to Seller Guarantor demanding that Seller Guarantor either cause
Sellers to pay the Guaranteed Obligations or to pay such Guaranteed Obligations
in the place and stead of Sellers.

2.                                       Representation and Warranties.  Seller
Guarantor represents and warrants to Buyer as follows:

(i)                             Seller Guarantor is duly organized, validly
existing, and in good standing under the laws of the State of Delaware.

(ii)                          Seller Guarantor has full corporate power and
authority (including all necessary approvals) to execute and deliver this
Guaranty and to perform its obligations hereunder and that this Guaranty has
been duly executed and delivered on behalf of Seller Guarantor by its duly
authorized representative.  This Guaranty constitutes the valid and legally
binding obligation of Seller Guarantor, enforceable against Seller Guarantor in
accordance with its terms and conditions except as such enforceability may be
limited by or subject to (A) any bankruptcy, insolvency, reorganization,
moratorium, fraudulent transfer or other similar applicable law relating to
creditors’ rights generally, and (B) general principles of equity (regardless of
whether such enforceability is considered in a proceeding in equity or at law). 
Seller Guarantor is not required to give any notice to, make any filing with, or
obtain any authorization, consent or approval of, any Governmental Authority or
any other person to perform its obligations under this Guaranty, except for such
notices, filings, authorizations, consents or approvals which the failure to
give, make or obtain, as the case may be, would not reasonably be expected to
materially and adversely affect the ability of Seller Guarantor to satisfy its
obligations hereunder.

(iii)                       Neither the execution and the delivery of this
Guaranty, nor the performance by Seller Guarantor of its obligations hereunder,
will violate any law or order of any Governmental Authority to which Seller
Guarantor is subject, or any Organizational Document or Contract to which Seller
Guarantor is a party, except as would not reasonably be expected to materially
and adversely affect the ability of Seller Guarantor to satisfy its obligations
hereunder.

3.                                       Seller Guarantor’s Obligations
Unconditional.  The obligations of Seller Guarantor hereunder shall remain in
full force and effect without regard to, and shall not be affected or impaired
by any of the following, any of which may be taken without the consent of, or
notice to, Seller Guarantor:

(i)                             any lack of legality, validity or enforceability
of any of the Closing Documents or any of the payment obligations thereunder;

(ii)                          any amendment, modification, addition, supplement,
extension or acceleration of or to any part of any Closing Document;

2

--------------------------------------------------------------------------------

(iii)                       any exercise or non-exercise by Buyer of any right
or privilege under the Closing Documents;

(iv)                      any extension (including without limitation extensions
of time for payment), renewal, amendment, restructuring or restatement of, or
any acceptance of late or partial payments under, any of the Closing Documents;

(v)                         any bankruptcy, insolvency, reorganization,
dissolution, liquidation or similar proceeding relating to Sellers or any
affiliate of Sellers (other than Seller Guarantor);

(vi)                      the existence of any facts or circumstances which
cause (or result in) any of the representations or warranties of Sellers under
the Closing Documents to be inaccurate; or

(vii)                   any other circumstance whatsoever (with or without
notice to or knowledge of Seller Guarantor) which may or might in any manner or
to any extent vary the risks of Seller Guarantor, or might otherwise constitute
a legal or equitable defense available to, or discharge of, a surety or a
guarantor, including without limitation, any right to require or claim that
resort be had to Sellers in respect of the Guaranteed Obligations.

4.                                       Independent Obligations.  The
obligations of Seller Guarantor hereunder are independent of the obligations of
Sellers and, in the event of any default hereunder, a separate action or actions
may be brought and prosecuted against Seller Guarantor whether or not Sellers
are joined therein or a separate action or actions are brought against Sellers. 
All remedies of Buyer are cumulative.

5.                                       Waiver.  Seller Guarantor
unconditionally and irrevocably waives:

(i)                             demands, protests, or notices as the same
pertain to Sellers;

(ii)                          any right to require Buyer to proceed against
Sellers or to exhaust any security held by Buyer or to pursue any other remedy;

(iii)                       any right to assert against Buyer, as a defense,
counterclaim, set-off, recoupment or cross claim in respect of the Guaranteed
Obligations, any defense (legal or equitable) or other claim which Seller
Guarantor may now or at any time hereafter have against Sellers or any other
person;

(iv)                      any defense based upon an election of remedies by
Buyer, unless the same would excuse performance by Sellers, under the Closing
Documents; and

3

--------------------------------------------------------------------------------

(v)                         any duty of Buyer to advise Seller Guarantor of any
information known to Buyer regarding Sellers or their ability to perform under
the Closing Documents.

6.                                       Continuing Guaranty.  Seller
Guarantor’s obligations under Section 1 of this Guaranty constitute a continuing
guaranty and shall continue in full force and effect until Sellers’ obligations
under the Closing Documents shall have been fully performed or otherwise
extinguished under the Closing Documents, at which time this Guaranty and all of
Seller Guarantor’s obligations hereunder shall terminate and expire.

7.                                       Reinstatement.  The obligations of
Seller Guarantor under this Guaranty shall be automatically reinstated if and to
the extent that for any reason any payment by or on behalf of Sellers or any
other person in respect of the Guaranteed Obligations is rescinded or must be
otherwise restored by any holder of any of such obligations, whether as a result
of any proceedings in bankruptcy or reorganization or otherwise.

8.                                       Third Parties.  This Guaranty shall not
confer any rights or remedies upon any person other than the parties hereto and
their successors and assigns.

9.                                       Successors and Assigns.  This Guaranty
shall be binding upon and inure to the benefit of the parties hereto and their
successors and assigns.  This Guaranty may not be assigned by Seller Guarantor
without the prior written consent of Buyer, except for an assignment or
delegation of all the rights and obligations of Seller Guarantor hereunder to a
corporation, partnership, trust or other entity that succeeds to all or
substantially all the assets and business of Seller Guarantor and that assumes
such obligations by contract, operation of law or otherwise.  Upon such
assignment or delegation and assumption of obligations, Seller Guarantor shall
be relieved of and fully discharged from all obligations hereunder, whether such
obligations arose before or after such assignment or delegation and assumption.

10.                                 Notices.  All notices, requests and other
communications hereunder must be in writing and will be deemed to have been duly
given only if delivered personally or by facsimile transmission or mailed (first
class postage prepaid) to the parties at the following addresses or facsimile
numbers:

If to Buyer:

Tokyo Crimson Energy Holdings Corporation

c/o M&C Corporate Services Limited

P.O. Box 309GT

Ugland House

South Church Street, Georgia Town

Grand Cayman, Cayman Islands

with a copy to:

4

--------------------------------------------------------------------------------

Tokyo Electric Power Company

1-1-3 Uchisaiwaicho

Chiyoda-ku, Tokyo 100-8560

Attn:  Takao Onuki

Tel:  81-3-4216-5593

Marubeni Corporation

1-4-2 Ohtemachi

Chiyoda-ku, Tokyo 100-8088

Attn:  Tomofumi Fukuda

Tel:  81-3-3286-9139

If to Seller Guarantor:

Mirant Corporation

1155 Perimeter Center West

Atlanta, Georgia 30338

Attention:  Steven B. Nickerson, Assistant General Counsel

Facsimile:  (678) 579-5951

with a copy to:

Skadden, Arps, Slate, Meagher & Flom LLP

1440 New York Avenue, N.W.

Washington, D.C.  20005

Attention:  Michael P. Rogan

Facsimile:  (202) 393-5760

All such notices, requests and other communications will (i) if delivered
personally to the address as provided in this Section 10, be deemed given upon
delivery, (ii) if delivered by facsimile transmission to the facsimile number as
provided in this Section 10, be deemed given upon receipt, and (iii) if
delivered by mail in the manner described above to the address as provided in
this Section 10, be deemed given upon receipt (in each case regardless of
whether such notice, request or other communication is received by any other
person to whom a copy of such notice, request or other communication is to be
delivered pursuant to this Section 10).  Any party from time to time may change
its address, facsimile number or other information for the purpose of notices to
that party by giving notice specifying such change to the other parties hereto.

11.                                 Governing Law and Forum.  This Guaranty
shall be governed by, and construed in accordance with, the law of the State of
New York without regard to principles of conflicts of law.  Each of the parties
hereto (a) consents to submit itself to the personal jurisdiction of any federal
court located in the State of New York or any New York state court in the event
any dispute arises out of this Guaranty, (b) agrees that it shall not attempt to
deny or defeat such personal jurisdiction by motion or other request

5

--------------------------------------------------------------------------------

for leave from any such court and (c) agrees that it shall not bring any action
relating to this Guaranty in any court other than a federal or state court
sitting in the State of New York.

12.                                 Entire Agreement and Amendments.  This
Guaranty embodies the entire agreement between Seller Guarantor and Buyer. 
There are no promises, terms, conditions or obligations other those contained
herein, and this Guaranty shall supercede all previous communications,
representations or agreements, either verbal or written, between Seller
Guarantor and Buyer.  No amendment of any provision of this Guaranty shall be
valid unless the amendment shall be in writing and signed by Buyer and Seller
Guarantor.

13.                                 Severability.  Any term or provision of this
Guaranty that is invalid or unenforceable in any situation in any jurisdiction
shall not affect the validity or enforceability of the remaining terms and
provisions hereof or the validity or enforceability of the offending term or
provision in any other situation or in any other jurisdiction.

14.                                 Counterparts.  This Guaranty may be executed
and delivered (including via facsimile) in any number of counterparts, each of
which will be deemed an original, but all of which together will constitute one
and the same instrument.

[Signature page follows]

6

--------------------------------------------------------------------------------

IN WITNESS WHEREOF, Seller Guarantor has executed this Guaranty as of the date
first above written.

 

MIRANT CORPORATION

 

 

 

 

 

 

 

 

By:

/s/ S. Linn Williams

 

 

 

Title:  Executive Vice President and General
Counsel

 

--------------------------------------------------------------------------------