EX-10.1






EXHIBIT 10.1




USEC Inc.




Common Stock




________




Underwriting Agreement




September 24, 2007



Goldman, Sachs & Co.,


Merrill, Lynch, Pierce, Fenner & Smith


Incorporated


As representatives of the several Underwriters


Named in Schedule I hereto,


c/o Goldman, Sachs & Co.,


85 Broad Street,


New York, New York 10004


Ladies and Gentlemen:



USEC Inc., a Delaware corporation (the “Company”), proposes, subject to the terms and
conditions stated herein, to issue and sell to the underwriters named in Schedule I hereto (the
“Underwriters”) an aggregate of 20,000,000 shares (the “Firm Securities”) and, at the election of
the Underwriters, up to 3,000,000 additional shares (the “Optional Securities”) of Common Stock
(“Stock”) of the Company (the Firm Securities and the Optional Securities that the Underwriters
elect to purchase pursuant to Section 2 hereof being collectively called the “Securities”).



1. The Company represents and warrants to, and agrees with, each of the Underwriters that:




(a) An “automatic shelf registration statement” as defined under Rule 405 under the
Securities Act of 1933, as amended (the “Act”) on Form S-3 (File No. 333-146063) in respect
of the Securities has been filed with the Securities and Exchange Commission (the
“Commission”) not earlier than three years prior to the date hereof; such registration
statement, and any post-effective amendment thereto, became effective on filing; and no
stop order suspending the effectiveness of such registration statement or any part thereof
has been issued and no proceeding for that purpose has been initiated or threatened by the
Commission, and no notice of objection of the Commission to the use of such registration
statement or any post-effective amendment thereto pursuant to Rule 401(g)(2) under the Act
has been received by the Company (the base prospectus filed as part of such registration
statement, in the form in which it has most recently been filed with the Commission on or
prior to the date of this Agreement, is hereinafter called the “Basic Prospectus”; any
preliminary prospectus (including any preliminary prospectus supplement) relating to the
Securities filed with the Commission pursuant to Rule 424(b) under the Act is hereinafter
called a “Preliminary Prospectus”; the various parts of such registration statement,
including all exhibits thereto but excluding Form T-1 and including any prospectus
supplement relating to the Securities that is filed with the Commission and deemed by
virtue of Rule 430B to be part of such registration statement, each as amended at the time
such part of the registration statement became effective, are hereinafter collectively
called the “Registration Statement”; the Basic Prospectus, as amended and supplemented by
any amendment or supplement related to the Securities immediately prior to the Applicable
Time (as defined in Section 1(c) hereof), is hereinafter called the “Pricing Prospectus”;
the form of the final prospectus relating to the Securities filed with the Commission
pursuant to Rule 424(b) under the Act in accordance with Section 5(a) hereof is hereinafter
called the “Prospectus”; any reference herein to the Basic Prospectus, the Pricing
Prospectus, any Preliminary Prospectus or the Prospectus shall be deemed to refer to and
include the documents incorporated by reference therein pursuant to Item 12 of Form S-3
under the Act, as of the date of such prospectus; any reference to any amendment or
supplement to the Basic Prospectus, any Preliminary Prospectus or the Prospectus shall be
deemed to refer to and include any post-effective amendment to the Registration Statement,
any prospectus supplement relating to the Securities filed with the Commission pursuant to
Rule 424(b) under the Act and any documents filed under the Securities Exchange Act of
1934, as amended (the “Exchange Act”), and incorporated therein, in each case after the
date of the Basic Prospectus, such Preliminary Prospectus, or the Prospectus, as the case
may be; any reference to any amendment to the Registration Statement shall be deemed to
refer to and include any annual report of the Company filed pursuant to Section 13(a) or
15(d) of the Exchange Act after the effective date of the Registration Statement that is
incorporated by reference in the Registration Statement; and any “issuer free writing
prospectus” as defined in Rule 433 under the Act relating to the Securities is hereinafter
called an “Issuer Free Writing Prospectus”);




(b) No order preventing or suspending the use of any Preliminary Prospectus or any
Issuer Free Writing Prospectus has been issued by the Commission, and each Preliminary
Prospectus, at the time of filing thereof, conformed in all material respects to the
requirements of the Act and the rules and regulations of the Commission thereunder, and 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, in the light of
the circumstances under which they were made, not misleading; provided, however, that this
representation and warranty shall not apply to any statements or omissions made in reliance
upon and in conformity with information furnished in writing to the Company by an
Underwriter through Goldman, Sachs & Co. or Merrill Lynch, Pierce, Fenner & Smith
Incorporated (together, the “Representatives”) expressly for use therein;




(c) For the purposes of this Agreement, the “Applicable Time” is 6:15pm (New York
City time) on the date of this Agreement; the Pricing Prospectus as supplemented by the
Issuer Free Writing Prospectus set forth in Schedule II(b) (the “Pricing Disclosure
Package”), as of the Applicable Time, did not include any untrue statement of a material
fact or omit to state any material fact necessary in order to make the statements therein,
in the light of the circumstances under which they were made, not misleading; and each
Issuer Free Writing Prospectus listed on Schedule II(a) and Schedule II(b) hereto does not
conflict with the information contained in the Registration Statement, the Pricing
Prospectus or the Prospectus and each such Issuer Free Writing Prospectus, as supplemented
by and taken together with the Pricing Disclosure Package as of the Applicable Time, did
not include any untrue statement of a material fact or omit to state any material fact
necessary in order to make the statements therein, in the light of the circumstances under
which they were made, not misleading; provided, however, that this representation and
warranty shall not apply to statements or omissions made in an Issuer Free Writing
Prospectus in reliance upon and in conformity with information furnished in writing to the
Company by an Underwriter through Goldman, Sachs & Co. expressly for use therein;




(d) The documents incorporated by reference in the Pricing Prospectus and the
Prospectus, when they became effective or were filed with the Commission, as the case may
be, conformed in all material respects to the requirements of the Act or the Exchange Act,
as applicable, and the rules and regulations of the Commission thereunder, and none of such
documents contained an untrue statement of a material fact or omitted to state a material
fact required to be stated therein or necessary to make the statements therein not
misleading; any further documents so filed and incorporated by reference in the Prospectus
or any further amendment or supplement thereto, when such documents become effective or are
filed with the Commission, as the case may be, will conform in all material respects to the
requirements of the Act or the Exchange Act, as applicable, and the rules and regulations
of the Commission thereunder and will 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; provided, however, that this representation and warranty
shall not apply to any statements or omissions made in reliance upon and in conformity with
information furnished in writing to the Company by an Underwriter through the
Representatives expressly for use therein; and no such documents were filed with the
Commission since the Commission’s close of business on the business day immediately prior
to the date of this Agreement and prior to the execution of this Agreement, except as set
forth on Schedule II(c) hereto;




(e) The Registration Statement conforms, and the Prospectus and any further amendments
or supplements to the Registration Statement and the Prospectus will conform, in all
material respects to the requirements of the Act and the rules and regulations of the
Commission thereunder and do not and will not, as of the applicable effective date as to
each part of the Registration Statement and as of the applicable filing date as to the
Prospectus and any amendment or supplement thereto, 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; provided, however, that this representation
and warranty shall not apply to any statements or omissions made in reliance upon and in
conformity with information furnished in writing to the Company by an Underwriter through
the Representatives expressly for use therein;




(f) Neither the Company nor any of its subsidiaries has sustained since the date of
the latest audited financial statements incorporated by reference in the Pricing Prospectus
any material loss or interference with its business from fire, explosion, flood or other
calamity, whether or not covered by insurance, or from any labor dispute or court or
governmental action, order or decree, otherwise than as set forth or contemplated in the
Pricing Prospectus except as would not, individually or in the aggregate, have a material
adverse effect on the management, properties, financial position, stockholders’ equity or
results of operations of the Company and its subsidiaries, taken as a whole (a “Material
Adverse Effect”); and, since the respective dates as of which information is given in the
Registration Statement and the Pricing Prospectus, there has not been any change in the
capital stock (except for de minimis issuances pursuant to the Company’s Direct Stock
Purchase Plan and 1999 Employee Stock Purchase Plan and de minimis issuances of common
stock upon the exercise of options outstanding on the date hereof) or long term debt of the
Company or any of its subsidiaries or any material adverse change, or any development
involving a prospective material adverse change, in or affecting the general affairs,
management, financial position, stockholders’ equity or results of operations of the
Company and its subsidiaries, taken as a whole, otherwise than as set forth or contemplated
in the Pricing Prospectus;




(g) The Company and its subsidiaries have good and marketable title to all personal
property (other than intellectual property, which is covered by Section 1(v) hereof) owned
by them, in each case that is material to the business of the Company and its subsidiaries,
taken as a whole, free and clear of all liens, encumbrances and defects except those (1)
pursuant to the Amended and Restated Revolving Credit Agreement dated as of August 18, 2005
among the Company, United States Enrichment Corporation and the lenders named therein, as
further amended, the (“Credit Agreement”) and the Amended and Restated Omnibus Pledge and
Security Agreement dated as of August 18, 2005 by the Company, United States Enrichment
Corporation, NAC Holding Inc. and NAC International Inc., in favor of JPMorgan Chase Bank,
N.A., as administrative and collateral agent for the lenders (the “Security Agreement” and
together with the Credit Agreement, the “Credit Documents”), (2) such as are described in
the Pricing Prospectus or (3) such as do not materially affect the value of such property
and do not materially interfere with the use made and proposed to be made of such property
by the Company and its subsidiaries; and any real property and buildings held under lease
by the Company and its subsidiaries are held by them under valid, subsisting and
enforceable leases with such exceptions as are not material and do not interfere with the
use made and proposed to be made of such property and buildings by the Company and its
subsidiaries;




(h) The Company has been duly incorporated and is validly existing as a corporation in
good standing under the laws of the State of Delaware, with corporate power and authority
to own or to lease its properties and conduct its business as described in the Pricing
Prospectus, and has been duly qualified as a foreign corporation for the transaction of
business and is in good standing under the laws of each other jurisdiction in which it owns
or leases properties or conducts any business so as to require such qualification, or is
subject to no material liability or disability by reason of the failure to be so qualified
in any such jurisdiction except where the failure to be so qualified would not,
individually or in the aggregate, have a Material Adverse Effect; and each of the
subsidiaries of the Company has been duly incorporated and is validly existing as a
corporation in good standing under the laws of its jurisdiction of incorporation;




(i) The Company has an authorized capitalization as set forth in the Pricing
Prospectus and all of the issued shares of capital stock of the Company have been duly and
validly authorized and issued and are fully paid and non-assessable and conform to the
description of the Stock contained in the Pricing Prospectus and the Prospectus; and all of
the issued shares of capital stock of each of the subsidiaries of the Company have been
duly and validly authorized and issued, are fully paid and non-assessable and (except for
directors’ qualifying shares and except as otherwise set forth in the Pricing Prospectus)
are owned directly or indirectly by the Company, free and clear of all liens, encumbrances,
equities or claims except as would not have a Material Adverse Effect;




(j) The unissued Securities to be issued and sold by the Company to the Underwriters
hereunder have been duly and validly authorized and, when issued and delivered against
payment therefor as provided herein, will be duly and validly issued and fully paid and
non-assessable and will conform to the description of the Securities contained in the
Prospectus;




(k) The issue and sale of the Securities and the compliance by the Company with this
Agreement and the consummation of the transactions herein contemplated will not: (1)
conflict with or result in a breach or violation of any of the terms or provisions of, or
constitute a default under, any indenture, mortgage, deed of trust, loan agreement or other
agreement or instrument to which the Company or any of its subsidiaries is a party or by
which the Company or any of its subsidiaries is bound or to which any of the property or
assets of the Company or any of its subsidiaries is subject, (2) result in any violation of
the provisions of the Certificate of Incorporation or By-laws of the Company or (3) result
in any violation of any statute or any order, rule or regulation of any court or
governmental agency or body having jurisdiction over the Company or any of its subsidiaries
or any of their properties; except in the case of clause (1) and (3) for any violation that
would not, individually or in the aggregate, have a Material Adverse Effect and would not
materially and adversely affect the consummation of the transactions contemplated herein;
and no consent, approval, authorization, order, registration or qualification of or with
any such court or governmental agency or body is required for the issue and sale of the
Securities or the consummation by the Company of the transactions contemplated by this
Agreement except such as have been obtained under the Act and such consents, approvals,
authorizations, registrations or qualifications as would not have a Material Adverse Effect
or as may be required under state securities or Blue Sky laws in connection with the
purchase and distribution of the Securities by the Underwriters;




(l) Neither the Company nor any of its subsidiaries is (1) in violation of its
Certificate of Incorporation or By-laws or (2) in default in the performance or observance
of any material obligation, covenant or condition contained in any indenture, mortgage,
deed of trust, loan agreement, lease or other agreement or instrument to which it is a
party or by which it or any of its properties may be bound;




(m) The statements set forth in the Pricing Prospectus and Prospectus under the
caption “Description of Capital Stock”, insofar as they purport to constitute a summary of
the terms of the Stock, under the captions “Certain Material United States Federal Income
Tax Consequences to Non-U.S. Holders” and “Underwriting”, insofar as they purport to
describe the provisions of the laws and documents referred to therein, are accurate,
complete and fair in all material respects;




(n) Other than as set forth in the Pricing Prospectus, there are no legal or
governmental proceedings pending to which the Company or any of its subsidiaries is a party
or of which any property of the Company or any of its subsidiaries is the subject which, if
determined adversely to the Company or any of its subsidiaries, would, individually or in
the aggregate, have a Material Adverse Effect; and, other than as set forth in the Pricing
Prospectus, to the Company’s knowledge, no such proceedings are threatened or contemplated
by governmental authorities or threatened by others;




(o) The Company is not and, after giving effect to the offering and sale of the
Securities and the application of the proceeds thereof, will not be an “investment
company”, as such term is defined in the Investment Company Act of 1940, as amended (the
“Investment Company Act”);




(p) (A) (i) At the time of filing the Registration Statement, (ii) at the time of the
most recent amendment thereto, if any, for the purposes of complying with Section 10(a)(3)
of the Act (whether such amendment was by post-effective amendment, incorporated report
filed pursuant to Section 13 or 15(d) of the Exchange Act or form of prospectus), and (iii)
at the time the Company or any person acting on its behalf (within the meaning, for this
clause only, of Rule 163(c) under the Act) made any offer relating to the Securities in
reliance on the exemption of Rule 163 under the Act, the Company was a “well-known seasoned
issuer” as defined in Rule 405 under the Act; and (B) at the earliest time after the filing
of the Registration Statement that the Company or another offering participant made a bona
fide offer (within the meaning of Rule 164(h)(2) under the Act) of the Securities, the
Company was not an “ineligible issuer” as defined in Rule 405 under the Act;




(q) PricewaterhouseCoopers LLP, who have audited certain financial statements of the
Company and its subsidiaries, and have audited the Company’s internal control over
financial reporting and management’s assessment thereof are independent registered public
accountants as required by the Act and the rules and regulations of the Commission
thereunder;




(r) The Company maintains a system of internal control over financial reporting (as
such term is defined in Rule 13a-15(f) under the Exchange Act) that complies with the
requirements of the Exchange Act and has been designed by the Company’s principal executive
officer and principal financial officer, or under their supervision, to provide reasonable
assurance regarding the reliability of financial reporting and the preparation of financial
statements for external purposes in accordance with generally accepted accounting
principles. As of the date of the latest audited financial statements included in the
Pricing Prospectus, the Company’s internal control over financial reporting is effective
and the Company is not aware of any material weaknesses in its internal control over
financial reporting;




(s) Since the date of the latest audited financial statements incorporated by
reference in the Pricing Prospectus, there has been no change in the Company’s internal
control over financial reporting that has materially affected, or is reasonably likely to
materially affect, the Company’s internal control over financial reporting;




(t) The Company maintains disclosure controls and procedures (as such term is defined
in Rule 13a-15(e) under the Exchange Act) that comply with the requirements of the Exchange
Act; such disclosure controls and procedures have been designed to ensure that material
information relating to the Company and its subsidiaries is made known to the Company’s
principal executive officer and principal financial officer by others within those
entities; and such disclosure controls and procedures are effective;




(u) The Company and its subsidiaries have all necessary consents, authorizations,
approvals, clearances, orders, certificates and permits of and from, and have made all
required declarations and filings with, all federal, state, local and other governmental
authorities (including, without limitation, the Nuclear Regulatory Commission (“NRC”), the
Department of Energy (“DOE”) and the Occupational Safety and Health Administration
(“OSHA”), all self-regulatory organizations and all courts and other tribunals, to own,
lease, license and use their respective properties and assets, as applicable, and to
conduct their respective businesses in the manner described in the Pricing Prospectus;
except such consents, authorizations, approvals, clearances, orders, certificates, permits,
declarations and filings the failure of which to have would not, individually or in the
aggregate, have a Material Adverse Effect;




(v) The Company or its subsidiaries own, or have the right to use, or can acquire on
reasonable terms, all material patents, patent rights, intellectual property licenses,
inventions, copyrights, know-how (including trade secrets and other unpatented and/or
unpatentable proprietary or confidential information, systems or procedures), trademarks,
service marks and trade names currently employed by the Company and its subsidiaries in
connection with the business now operated by the Company and its subsidiaries except as
would not, individually or in the aggregate, have a Material Adverse Effect and neither the
Company nor any of its subsidiaries has received any notice of infringement of or conflict
with asserted rights of others with respect to any of the foregoing that if resolved
against the Company or its subsidiaries, would, individually or in the aggregate, have a
Material Adverse Effect;




(w) Except as set forth in the Pricing Prospectus, the Company and its subsidiaries
(1) are and have been in compliance with all applicable federal, state and local laws,
including common law, and regulations, relating to the protection of human health and
safety, the environment or hazardous or toxic substances or wastes, pollutants or
contaminants (“Environmental Laws”), (2) have received all permits, licenses or other
approvals required of them under applicable Environmental Laws to conduct their respective
businesses and (3) are in compliance with all terms and conditions of any such permit,
license or approval, except in the case of each of clauses (1), (2) and (3), to the extent
that the failure to so comply or receive, as applicable, would not, individually or in the
aggregate, have a Material Adverse Effect;




(x) Except as set forth in the Pricing Prospectus, there are no costs or liabilities
associated with Environmental Laws (including, without limitation, any capital or operating
expenditures required for clean-up, closure of properties or compliance with Environmental
Laws or any permit, license or approval, any related constraints on operating activities
and any potential liabilities to third parties) that would, after taking into account
existing indemnities from the DOE and after giving effect to the Privatization Act, Chapter
1, Title 3 of Public Law 104-134, and the Energy Policy Act of 1992, Public Law 102-486,
individually or in the aggregate, have a Material Adverse Effect;




(y) Other than as disclosed in the Pricing Prospectus, no labor dispute with the
employees of the Company or any of its subsidiaries exists, or, to the knowledge of the
Company, is imminent, which would, individually or in the aggregate, have a Material
Adverse Effect; and




(z) Except as would not, individually or in the aggregate have a Material Adverse
Effect, (1) the Company and its subsidiaries comply with the Employee Retirement Income
Security Act of 1974, as amended (“ERISA”), the Internal Revenue Code of 1986, as amended
(the “Code”) and the terms of each plan, if and to the extent applicable, with respect to
each “pension plan” (as defined in Section 3(2) of ERISA) maintained by the Company or any
of its subsidiaries and (2) none of the Company or its subsidiaries has incurred, or
expects to incur, any liability (other than contributions made in accordance with the terms
of applicable plans) under Title IV of ERISA with respect to any ongoing, frozen or
terminated “pension plan” that is subject to Title IV of ERISA and is, or was, maintained
by the Company, its subsidiaries or any other person or entity that, together with the
Company and its subsidiaries, is treated as a single employer under Section 414 of the
Code.



2. Subject to the terms and conditions herein set forth, (a) the Company agrees to issue and
sell to each of the Underwriters, and each of the Underwriters agrees, severally and not jointly,
to purchase from the Company, at a purchase price per share of $9.32, the number of Firm Securities
set forth opposite the name of such Underwriter in Schedule I hereto, and (b) in the event and to
the extent that the Underwriters shall exercise the election to purchase Optional Securities as
provided below, the Company agrees to issue and sell to each of the Underwriters, and each of the
Underwriters agrees, severally and not jointly, to purchase from the Company, at the purchase price
per share set forth in clause (a) of this Section 2, that portion of the number of Optional
Securities as to which such election shall have been exercised (to be adjusted by you so as to
eliminate fractional shares) determined by multiplying such number of Optional Securities by a
fraction, the numerator of which is the maximum number of Optional Securities which such
Underwriter is entitled to purchase as set forth opposite the name of such Underwriter in Schedule
I hereto and the denominator of which is the maximum number of Optional Securities that all of the
Underwriters are entitled to purchase hereunder.



The Company hereby grants to the Underwriters the right to purchase at their election up to 3
million Optional Securities, at the purchase price per share set forth in the paragraph above, for
the sole purpose of covering sales of shares in excess of the number of Firm Securities, provided
that the purchase price per Optional Share shall be reduced by an amount per share equal to any
dividends or distributions declared by the Company and payable on the Firm Securities but not
payable on the Optional Securities. Any such election to purchase Optional Securities may be
exercised only by written notice from you to the Company, given within a period of 30 calendar days
after the date of this Agreement, setting forth the aggregate number of Optional Securities to be
purchased and the date on which such Optional Securities are to be delivered, as determined by you
but in no event earlier than the First Time of Delivery (as defined in Section 4 hereof) or, unless
you and the Company otherwise agree in writing, earlier than two or later than ten business days
after the date of such notice.



3. Upon the authorization by you of the release of the Firm Securities, the several
Underwriters propose to offer the Firm Securities for sale upon the terms and conditions set forth
in the Prospectus.



4. (a) The Securities to be purchased by each Underwriter hereunder, in definitive form, and
in such authorized denominations and registered in such names as Goldman, Sachs & Co. may request
upon at least forty-eight hours’ prior notice to the Company shall be delivered by or on behalf of
the Company to Goldman, Sachs & Co., through the facilities of the Depository Trust Company
(“DTC”), for the account of such Underwriter, against payment by or on behalf of such Underwriter
of the purchase price therefor by wire transfer of Federal (same-day) funds to the account
specified by the Company to Goldman, Sachs & Co. at least forty-eight hours in advance. The
Company will cause the certificates representing the Securities to be made available for checking
and packaging at least twenty-four hours prior to the Time of Delivery (as defined below) with
respect thereto at the office of DTC or its designated custodian (the “Designated Office”). The
time and date of such delivery and payment shall be, with respect to the Firm Shares, 9:30 a.m.,
New York City time, on September 28, 2007 or such other time and date as Goldman, Sachs & Co. and
the Company may agree upon in writing, and, with respect to the Optional Shares, 9:30 a.m., New
York City time, on the date specified by Goldman, Sachs & Co. in the written notice given by
Goldman, Sachs & Co. of the Underwriters’ election to purchase such Optional Shares, or such other
time and date as Goldman, Sachs & Co. and the Company may agree upon in writing. Such time and
date for delivery of the Firm Shares is herein called the “First Time of Delivery”, such time and
date for delivery of the Optional Shares, if not the First Time of Delivery, is herein called the
“Second Time of Delivery”, and each such time and date for delivery is herein called a “Time of
Delivery”.



(b) The documents to be delivered at each Time of Delivery by or on behalf of the parties
hereto pursuant to Section 8 hereof, including the cross-receipt for the Securities and any
additional documents requested by the Underwriters pursuant to Section 8(k) hereof, will be
delivered at the offices of Sullivan & Cromwell LLP, 1701 Pennsylvania Ave. N.W., Washington, D.C.
20006 (the “Closing Location”), and the Securities will be delivered at the Designated Office, all
at the Time of Delivery. A meeting will be held at the Closing Location at 5:00 p.m., New York
City time, on the New York Business Day next preceding such Time of Delivery, at which meeting the
final drafts of the documents to be delivered pursuant to the preceding sentence will be available
for review by the parties hereto. For the purposes of this Section 4, “New York Business Day”
shall mean each Monday, Tuesday, Wednesday, Thursday and Friday which is not a day on which banking
institutions in New York City are generally authorized or obligated by law or executive order to
close.



5. The Company agrees with each of the Underwriters:



(a) To prepare the Prospectus in a form approved by you and to file such Prospectus pursuant
to Rule 424(b) under the Act not later than the Commission’s close of business on the second
business day following the date of this Agreement; to make no further amendment or any supplement
to the Registration Statement, the Basic Prospectus or the Prospectus prior to such Time of
Delivery which shall be disapproved by you promptly after reasonable notice thereof; to advise you,
promptly after it receives notice thereof, of the time when any amendment to the Registration
Statement has been filed or becomes effective or any amendment or supplement to the Prospectus has
been filed and to furnish you with copies thereof; to file promptly all other material required to
be filed by the Company with the Commission pursuant to Rule 433(d) under the Act; to file promptly
all reports and any definitive proxy or information statements required to be filed by the Company
with the Commission pursuant to Section 13(a), 13(c), 14 or 15(d) of the Exchange Act subsequent to
the date of the Prospectus and for so long as the delivery of a prospectus (or in lieu thereof, the
notice referred to in Rule 173(a) under the Act) is required in connection with the offering or
sale of the Securities; to advise you, promptly after it receives notice thereof, of the issuance
by the Commission of any stop order or of any order preventing or suspending the use of any
Preliminary Prospectus or other prospectus in respect of the Securities, of any notice of objection
of the Commission to the use of the Registration Statement or any post-effective amendment thereto
pursuant to Rule 401(g)(2) under the Act, of the suspension of the qualification of the Securities
for offering or sale in any jurisdiction, of the initiation or threatening of any proceeding for
any such purpose, or of any request by the Commission for the amending or supplementing of the
Registration Statement or the Prospectus or for additional information; and, in the event of the
issuance of any stop order or of any order preventing or suspending the use of any Preliminary
Prospectus or other prospectus or suspending any such qualification, to promptly use its best
efforts to obtain the withdrawal of such order; and in the event of any such issuance of a notice
of objection, promptly to take such steps including, without limitation, amending the Registration
Statement or filing a new registration statement, at its own expense, as may be necessary to permit
offers and sales of the Securities by the Underwriters (references herein to the Registration
Statement shall include any such amendment or new registration statement);



(b) If required by Rule 430B(h) under the Act, to prepare a form of prospectus in a form
approved by you, and to file such form of prospectus pursuant to Rule 424(b) under the Act not
later than may be required by Rule 424(b) under the Act; and to make no further amendment or
supplement to such form of prospectus which shall be disapproved by you promptly after reasonable
notice therereof;



(c) If by the third anniversary (the “Renewal Deadline”) of the initial effective date of the
Registration Statement, any of the Securities remain unsold by the Underwriters, the Company will
file, if it has not already done so and is eligible to do so, a new automatic shelf registration
statement relating to the Securities, in a form reasonably satisfactory to you. If at the Renewal
Deadline the Company is no longer eligible to file an automatic shelf registration statement, the
Company will, if it has not already done so, file a new shelf registration statement relating to
the Securities, in a form satisfactory to you and will use its best efforts to cause such
registration statement to be declared effective within 180 days after the Renewal Deadline. The
Company will take all other action necessary or appropriate to permit the public offering and sale
of the Securities to continue as contemplated in the expired registration statement relating to the
Securities. References herein to the Registration Statement shall include such new automatic shelf
registration statement or such new shelf registration statement, as the case may be;



(d) Promptly from time to time to take such action as you may reasonably request to qualify
the Securities for offering and sale under the securities laws of such jurisdictions as you may
request and to comply with such laws so as to permit the continuance of sales and dealings therein
in such jurisdictions for as long as may be necessary to complete the distribution of the
Securities, provided that in connection therewith the Company shall not be required to qualify as a
foreign corporation or to file a general consent to service of process in any jurisdiction;



(e) Prior to 10:00 a.m., New York City time, on the New York Business Day next succeeding the
date of this Agreement and from time to time, to furnish the Underwriters with written and
electronic copies of the Prospectus in New York City in such quantities as you may reasonably
request, and, if the delivery of a prospectus (or in lieu thereof, the notice referred to in Rule
173(a) under the Act) is required at any time prior to the expiration of nine months after the time
of issue of the Prospectus in connection with the offering or sale of the Securities and if at such
time any event shall have occurred as a result of which the Prospectus as then amended or
supplemented would include an untrue statement of a material fact or omit to state any material
fact necessary in order to make the statements therein, in the light of the circumstances under
which they were made when such Prospectus (or in lieu thereof, the notice referred to in Rule
173(a) under the Act) is delivered, not misleading, or, if for any other reason it shall be
necessary during such same period to amend or supplement the Prospectus or to file under the
Exchange Act any document incorporated by reference in the Prospectus in order to comply with the
Act or the Exchange Act, to notify you and upon your request to file such document and to prepare
and furnish without charge to each Underwriter and to any dealer in securities as many written and
electronic copies as you may from time to time reasonably request of an amended Prospectus or a
supplement to the Prospectus which will correct such statement or omission or effect such
compliance; and in case any Underwriter is required to deliver a prospectus (or in lieu thereof,
the notice referred to in Rule 173(a) under the Act) in connection with sales of any of the
Securities at any time nine months or more after the time of issue of the Prospectus, upon your
request but at the expense of such Underwriter, to prepare and deliver to such Underwriter as many
written and electronic copies as you may request of an amended or supplemented Prospectus complying
with Section 10(a)(3) of the Act;



(f) To make generally available to its securityholders as soon as practicable, but in any
event not later than sixteen months after the effective date of the Registration Statement (as
defined in Rule 158(c) under the Act), an earnings statement of the Company and its subsidiaries
(which need not be audited) complying with Section 11(a) of the Act and the rules and regulations
of the Commission thereunder (including, at the option of the Company, Rule 158);



(g) During the period beginning from the date hereof and continuing to and including the date
90 days after the date of the Prospectus (the “Lock-Up Period”), not to offer, sell, contract to
sell, pledge, grant any option to purchase, make any short sale or otherwise dispose, except as
provided hereunder, of any securities of the Company that are substantially similar to the
Securities, including but not limited to any options or warrants to purchase shares of Stock or any
securities that are convertible into or exchangeable for, or that represent the right to receive,
Stock or any such substantially similar securities (other than (1) the offer and sale of Securities
pursuant to this Agreement, (2) the offer and sale of 3.0% senior convertible notes by the Company
pursuant to the Underwriting Agreement, dated the date hereof, between the Company, Goldman, Sachs
& Co., and Wachovia Capital Markets, LLC, as representatives of the several Underwriters named
therein relating to the common stock of the Company, which shall occur concurrently with this offer
and sale of Securities, which shall occur concurrently with this offer and sale of Securities, (3)
the grant of stock options, restricted stocks, restricted stock units or other equity awards
pursuant to the USEC Inc. 1999 Equity Incentive Plan, as amended, (4) issuances pursuant to the
Dividend Reinvestment Direct Stock Purchase Plan, USEC Inc. 1999 Employee Stock Purchase Plan, as
amended, (5) the issuance of Stock pursuant to the exercise of such options or settlement of such
equity awards or (6) upon the conversion or exchange of convertible or exchangeable securities
outstanding as of the date of this Agreement), without your prior written consent; provided,
however, that (1) if during the last 17 days of the initial Lock-Up Period, the Company releases
earnings results or announces material news or a material event or (2) prior to the expiration of
the initial Lock-Up Period, the Company announces that it will release earnings results during the
15-day period following the last day of the initial Lock-Up Period, then in each case the Lock-Up
Period will be automatically extended until the expiration of the 18-day period beginning on the
date of release of the earnings results or the announcement of the material news or material event,
as applicable, unless each of the Representatives waives, in writing, such extension; provided,
further, the Company will provide each of the Representatives and each stockholder subject to the
Lock-Up Period pursuant to the letters described in Section 8(j) with prior notice of any such
announcement that gives rise to an extension of the Lock-up Period;



(h) To pay the required Commission filing fees relating to the Securities within the time
required by Rule 456(b)(1) under the Act without regard to the proviso therein and otherwise in
accordance with Rules 456(b) and 457(r) under the Act;



(i) To use the net proceeds received by it from the sale of the Securities pursuant to this
Agreement in the manner specified in the Pricing Prospectus under the caption “Use of Proceeds”;
and



(j) To use its commercially reasonable efforts to list, subject to notice of issuance, the
Securities on the New York Stock Exchange (the “Exchange).



6.



(a) (i) The Company represents and agrees that without the prior consent of Goldman, Sachs &
Co., it has not made and will not make any offer relating to the Securities that would constitute a
“free writing prospectus” as defined in Rule 405 under the Act;



(ii) Each Underwriter represents and agrees that, without the prior consent of each of the
Company and the Representatives, it has not made and will not make any offer relating to the
Securities that would constitute a free writing prospectus; and



(iii) The Company and the Underwriters agree that any such free writing prospectus described
in clauses (i) and (ii) of this Section 6(a), the use of which has been consented to by the Company
and Goldman, Sachs & Co., is listed on Schedule II(a) and Schedule II(b) hereto;



(b) The Company has complied and will comply with the requirements of Rule 433 under the Act
applicable to any Issuer Free Writing Prospectus, including timely filing with the Commission or
retention where required and legending; and



(c) The Company agrees that if at any time following issuance of an Issuer Free Writing
Prospectus any event occurred or occurs as a result of which such Issuer Free Writing Prospectus
would conflict with the information in the Registration Statement, the Pricing Prospectus or the
Prospectus or would include an untrue statement of a material fact or omit to state any material
fact necessary in order to make the statements therein, in the light of the circumstances then
prevailing, not misleading, the Company will give prompt notice thereof to Goldman, Sachs & Co.
and, if requested by Goldman, Sachs & Co., will prepare and furnish without charge to each
Underwriter an Issuer Free Writing Prospectus or other document that will correct such conflict,
statement or omission; provided, however, that this representation and warranty shall not apply to
any statements or omissions in an Issuer Free Writing Prospectus made in reliance upon and in
conformity with information furnished in writing to the Company by an Underwriter through Goldman,
Sachs & Co. expressly for use therein.



7. The Company covenants and agrees with the several Underwriters that the Company will pay or
cause to be paid the following: (i) the fees, disbursements and expenses of the Company’s counsel
and accountants in connection with the registration of the Securities under the Act and all other
expenses in connection with the preparation, printing, reproduction and filing of the Registration
Statement, the Basic Prospectus, any Preliminary Prospectus, any Issuer Free Writing Prospectus and
the Prospectus and amendments and supplements thereto and the mailing and delivering of copies
thereof to the Underwriters and dealers; (ii) the cost of printing or producing any Agreement among
Underwriters, this Agreement, the Blue Sky Memorandum, closing documents (including any
compilations thereof) and any other documents in connection with the offering, purchase, sale and
delivery of the Securities; (iii) all expenses in connection with the qualification of the
Securities for offering and sale under state securities laws as provided in Section 5(d) hereof,
including the fees and disbursements of counsel for the Underwriters in connection with such
qualification and in connection with the Blue Sky survey; (iv) all fees and expenses in connection
with listing the Securities on the Exchange; (v) the cost of preparing the Securities; (vi) the
cost and charges of any transfer agent or registrar; and (vii) all other costs and expenses
incident to the performance of its obligations hereunder which are not otherwise specifically
provided for in this Section. It is understood, however, that, except as provided in this Section,
and Sections 9 and 12 hereof, the Underwriters will pay all of their own costs and expenses,
including the fees of their counsel, transfer taxes on resale of any of the Securities by them, and
any advertising expenses connected with any offers they may make.



8. The obligations of the Underwriters hereunder, as to the Securities to be delivered at each
Time of Delivery, shall be subject, in their discretion, to the condition that all representations
and warranties and other statements of the Company herein are, at and as of such Time of Delivery,
true and correct, the condition that the Company shall have performed all of its obligations
hereunder theretofore to be performed, and the following additional conditions:



(a) The Prospectus shall have been filed with the Commission pursuant to Rule 424(b) under the
Act within the applicable time period prescribed for such filing by the rules and regulations under
the Act and in accordance with Section 5(a) hereof; all material required to be filed by the
Company pursuant to Rule 433(d) under the Act shall have been filed with the Commission within the
applicable time period prescribed for such filings by Rule 433; no stop order suspending the
effectiveness of the Registration Statement or any part thereof shall have been issued and no
proceeding for that purpose shall have been initiated or threatened by the Commission and no notice
of objection of the Commission to the use of the Registration Statement or any post-effective
amendment thereto pursuant to Rule 401(g)(2) under the Act shall have been received; no stop order
suspending or preventing the use of the Prospectus or any Issuer Free Writing Prospectus shall have
been initiated or threatened by the Commission; and all requests for additional information on the
part of the Commission shall have been complied with to your reasonable satisfaction;



(b) Sullivan & Cromwell LLP, counsel for the Underwriters, shall have furnished to you such
written opinion or opinions, dated such Time of Delivery, in form and substance reasonably
satisfactory to you, with respect to such matters as you may reasonably request, and such counsel
shall have received such papers and information as they may reasonably request to enable them to
pass upon such matters;



(c) Latham & Watkins LLP, counsel for the Company, shall have furnished to you their written
opinions in form and substance substantially in the forms attached as Annexes II(a) and (b) hereto,
dated such Time of Delivery;



(d) Allen Lear, Interim General Counsel of the Company, shall have furnished to you his
written opinion in form and substance substantially in the form attached as Annex II(c) hereto,
dated such Time of Delivery;



(e) Morgan, Lewis & Bockius LLP, regulatory counsel for the Company, shall have furnished to
you their written opinion in form and substance substantially in the form attached as Annex II(d)
hereto, dated such Time of Delivery;



(f) On the date of the Prospectus at a time prior to the execution of this Agreement, at 9:30
a.m. (New York City time) on the effective date of any post effective amendment to the Registration
Statement filed subsequent to the date of this Agreement and also at each Time of Delivery,
PricewaterhouseCoopers LLP shall have furnished to you a letter or letters, dated the respective
dates of delivery thereof, in form and substance reasonably satisfactory to you and which
PricewaterhouseCoopers LLP is willing to perform and report upon, to the effect set forth in Annex
I hereto;



(g) (i) Neither the Company nor any of its subsidiaries shall have sustained since the date of
the latest audited financial statements incorporated by reference in the Pricing Prospectus any
loss or interference with its business from fire, explosion, flood or other calamity, whether or
not covered by insurance, or from any labor dispute or court or governmental action, order or
decree, otherwise than as set forth or contemplated in the Pricing Prospectus, and (ii) since the
respective dates as of which information is given in the Pricing Prospectus there shall not have
been any change in the capital stock (except for de minimis issuances pursuant to the Company’s
Direct Stock Purchase Plan and 1999 Employee Stock Purchase Plan and de minimis issuances of common
stock upon the exercise of options outstanding on the date hereof) or long term debt of the Company
or any of its subsidiaries or any change, or any development involving a prospective change, in or
affecting the general affairs, management, financial position, stockholders’ equity or results of
operations of the Company and its subsidiaries, taken as a whole, otherwise than as set forth or
contemplated in the Pricing Prospectus, the effect of which, in any such case described in clause
(i) or (ii), is in your opinion so material and adverse as to make it impracticable or inadvisable
to proceed with the public offering or the delivery of the Securities being delivered at such Time
of Delivery on the terms and in the manner contemplated in the Prospectus;



(h) On or after the Applicable Time (i) no downgrading shall have occurred in the rating
accorded the Company’s debt securities by any “nationally recognized statistical rating
organization”, as that term is defined by the Commission for purposes of Rule 436(g)(2) under the
Act, and (ii) no such organization shall have publicly announced that it has under surveillance or
review, with possible negative implications, its rating of any of the Company’s debt securities;



(i) On or after the Applicable Time there shall not have occurred any of the following: (i) a
suspension or material limitation in trading in securities generally on the Exchange; (ii) a
suspension or material limitation in trading in the Company’s securities on the Exchange; (iii) a
general moratorium on commercial banking activities declared by either Federal or New York State
authorities or a material disruption in commercial banking or securities settlement or clearance
services in the United States; (iv) the outbreak or escalation of hostilities involving the United
States or the declaration by the United States of a national emergency or war or (v) the occurrence
of any other calamity or crisis or any change in financial, political or economic conditions in the
United States or elsewhere, if the effect of any such event specified in clause (iv) or (v) in the
judgment of the Representatives makes it impracticable or inadvisable to proceed with the public
offering or the delivery of the Securities being delivered at such Time of Delivery on the terms
and in the manner contemplated in the Prospectus;



(j) The Company shall have complied with the provisions of Section 5(e) hereof with respect to
the furnishing of prospectuses on the New York Business Day next succeeding the date of this
Agreement;



(k) Any actions required for the Securities to be duly listed for quotation on the Exchange
shall have been taken;



(l) The Company has obtained and delivered to the Underwriters executed copies of an agreement
from each of the stockholders listed on Annex III hereto, substantially to the effect set forth in
Section 5(g) hereof in form and substance satisfactory to you;



(m) The Company shall have furnished or caused to be furnished to you at such Time of Delivery
certificates of officers of the Company reasonably satisfactory to the Representatives as to the
accuracy of the representations and warranties of the Company herein at and as of such time, as to
the performance by the Company of all of its obligations hereunder to be performed at or prior to
such time, as to the matters set forth in subsections (a) and (e) of this Section and as to such
other matters as the Representatives may reasonably request; and



(m) The sale of the 3.0% convertible senior notes by the Company pursuant to the underwriting
agreement, dated the date hereof, between the Company and Goldman, Sachs & Co. and Wachovia Capital
Markets, LLC, as representatives of the underwriters named therein, shall have occurred prior to or
concurrently with the sale of the Securities hereunder.



9. (a) The Company will indemnify and hold harmless each Underwriter against any losses,
claims, damages or liabilities, joint or several, to which such Underwriter may become subject,
under the Act or otherwise, insofar as such losses, claims, damages or liabilities (or actions in
respect thereof) arise out of or are based upon an untrue statement or alleged untrue statement of
a material fact contained in the Registration Statement, the Basic Prospectus, any Preliminary
Prospectus, the Pricing Prospectus or the Prospectus, or any amendment or supplement thereto, any
Issuer Free Writing Prospectus or any “issuer information” filed or required to be filed pursuant
to Rule 433(d) under the Act, or arise out of or are based upon the omission or alleged omission to
state therein a material fact required to be stated therein or necessary to make the statements
therein not misleading, and will reimburse each Underwriter for any legal or other expenses
reasonably incurred by such Underwriter in connection with investigating or defending any such
action or claim as such expenses are incurred; provided, however, that the Company shall not be
liable in any such case to the extent that any such loss, claim, damage or liability arises out of
or is based upon an untrue statement or alleged untrue statement or omission or alleged omission
made in the Registration Statement, the Basic Prospectus, any Preliminary Prospectus, the Pricing
Prospectus or the Prospectus, or any amendment or supplement thereto, or any Issuer Free Writing
Prospectus, in reliance upon and in conformity with written information furnished to the Company by
any Underwriter through the Representatives expressly for use therein.



(b) Each Underwriter will indemnify and hold harmless the Company against any losses, claims,
damages or liabilities to which the Company may become subject, under the Act or otherwise, insofar
as such losses, claims, damages or liabilities (or actions in respect thereof) arise out of or are
based upon an untrue statement or alleged untrue statement of a material fact contained in the
Registration Statement, the Basic Prospectus, any Preliminary Prospectus, the Pricing Prospectus or
the Prospectus, or any amendment or supplement thereto, or any Issuer Free Writing Prospectus, or
arise out of or are based upon the omission or alleged omission to state therein a material fact
required to be stated therein or necessary to make the statements therein not misleading, in each
case to the extent, but only to the extent, that such untrue statement or alleged untrue statement
or omission or alleged omission was made in the Registration Statement, the Basic Prospectus, any
Preliminary Prospectus, the Pricing Prospectus or the Prospectus or any such amendment or
supplement thereto, or any Issuer Free Writing Prospectus, in reliance upon and in conformity with
written information furnished to the Company by such Underwriter through the Representatives
expressly for use therein; and will reimburse the Company for any legal or other expenses
reasonably incurred by the Company in connection with investigating or defending any such action or
claim as such expenses are incurred.



(c) Promptly after receipt by an indemnified party under subsection (a) or (b) above of notice
of the commencement of any action, such indemnified party shall, if a claim in respect thereof is
to be made against the indemnifying party under such subsection, notify the indemnifying party in
writing of the commencement thereof; but the omission so to notify the indemnifying party shall not
relieve it from any liability which it may have to any indemnified party otherwise than under such
subsection. In case any such action shall be brought against any indemnified party and it shall
notify the indemnifying party of the commencement thereof, the indemnifying party shall be entitled
to participate therein and, to the extent that it shall wish, jointly with any other indemnifying
party similarly notified, to assume the defense thereof, with counsel satisfactory to such
indemnified party (who shall not, except with the consent of the indemnified party, be counsel to
the indemnifying party), and, after notice from the indemnifying party to such indemnified party of
its election so to assume the defense thereof, the indemnifying party shall not be liable to such
indemnified party under such subsection for any legal expenses of other counsel or any other
expenses, in each case subsequently incurred by such indemnified party, in connection with the
defense thereof other than reasonable costs of investigation. No indemnifying party shall, without
the written consent of the indemnified party, effect the settlement or compromise of, or consent to
the entry of any judgment with respect to, any pending or threatened action or claim in respect of
which indemnification or contribution may be sought hereunder (whether or not the indemnified party
is an actual or potential party to such action or claim) unless such settlement, compromise or
judgment (i) includes an unconditional release of the indemnified party from all liability arising
out of such action or claim and (ii) does not include a statement as to or an admission of fault,
culpability or a failure to act, by or on behalf of any indemnified party.



(d) If the indemnification provided for in this Section 9 is unavailable to or insufficient to
hold harmless an indemnified party under subsection (a) or (b) above in respect of any losses,
claims, damages or liabilities (or actions in respect thereof) referred to therein, then each
indemnifying party shall contribute to the amount paid or payable by such indemnified party as a
result of such losses, claims, damages or liabilities (or actions in respect thereof) in such
proportion as is appropriate to reflect the relative benefits received by the Company on the one
hand and the Underwriters on the other from the offering of the Securities. If, however, the
allocation provided by the immediately preceding sentence is not permitted by applicable law or if
the indemnified party failed to give the notice required under subsection (c) above, then each
indemnifying party shall contribute to such amount paid or payable by such indemnified party in
such proportion as is appropriate to reflect not only such relative benefits but also the relative
fault of the Company on the one hand and the Underwriters on the other in connection with the
statements or omissions which resulted in such losses, claims, damages or liabilities (or actions
in respect thereof), as well as any other relevant equitable considerations. The relative benefits
received by the Company on the one hand and the Underwriters on the other shall be deemed to be in
the same proportion as the total net proceeds from the offering (before deducting expenses)
received by the Company bear to the total underwriting discounts and commissions received by the
Underwriters, in each case as set forth in the table on the cover page of the Prospectus. The
relative fault shall be determined by reference to, among other things, whether the untrue or
alleged untrue statement of a material fact or the omission or alleged omission to state a material
fact relates to information supplied by the Company on the one hand or the Underwriters on the
other and the parties’ relative intent, knowledge, access to information and opportunity to correct
or prevent such statement or omission. The Company and the Underwriters agree that it would not be
just and equitable if contribution pursuant to this subsection (d) were determined by pro rata
allocation (even if the Underwriters were treated as one entity for such purpose) or by any other
method of allocation which does not take account of the equitable considerations referred to above
in this subsection (d). The amount paid or payable by an indemnified party as a result of the
losses, claims, damages or liabilities (or actions in respect thereof) referred to above in this
subsection (d) shall be deemed to include any legal or other expenses reasonably incurred by such
indemnified party in connection with investigating or defending any such action or claim.
Notwithstanding the provisions of this subsection (d), no Underwriter shall be required to
contribute any amount in excess of the amount by which the total price at which the Securities
underwritten by it and distributed to the public were offered to the public exceeds the amount of
any damages which such Underwriter has otherwise been required to pay by reason of such untrue or
alleged untrue statement or omission or alleged omission. No person guilty of fraudulent
misrepresentation (within the meaning of Section 11(f) of the Act) shall be entitled to
contribution from any person who was not guilty of such fraudulent misrepresentation. The
Underwriters’ obligations in this subsection (d) to contribute are several in proportion to their
respective underwriting obligations and not joint.



(e) The obligations of the Company under this Section 9 shall be in addition to any liability
which the Company may otherwise have and shall extend, upon the same terms and conditions, to each
person, if any, who controls any Underwriter within the meaning of the Act and each broker-dealer
affiliate of any Underwriter; and the obligations of the Underwriters under this Section 9 shall be
in addition to any liability which the respective Underwriters may otherwise have and shall extend,
upon the same terms and conditions, to each officer and director of the Company and to each person,
if any, who controls the Company within the meaning of the Act.



10. (a) If any Underwriter shall default in its obligation to purchase the Securities that it
has agreed to purchase hereunder, you may in your discretion arrange for you or another party or
other parties to purchase such Securities on the terms contained herein. If within 36 hours after
such default by any Underwriter you do not arrange for the purchase of such Securities, then the
Company shall be entitled to a further period of 36 hours within which to procure another party or
other parties reasonably satisfactory to you to purchase such Securities on such terms. In the
event that, within the respective prescribed periods, you notify the Company that you have so
arranged for the purchase of such Securities, or the Company notifies you that it has so arranged
for the purchase of such Securities, you or the Company shall have the right to postpone such Time
of Delivery for a period of not more than seven days, in order to effect whatever changes may
thereby be made necessary in the Registration Statement or the Prospectus, or in any other
documents or arrangements, and the Company agrees to file promptly any amendments or supplements to
the Registration Statement or the Prospectus that in your opinion may thereby be made necessary.
The term “Underwriter” as used in this Agreement shall include any person substituted under this
Section with like effect as if such person had originally been a party to this Agreement with
respect to such Securities.



(b) If, after giving effect to any arrangements for the purchase of the Securities of a
defaulting Underwriter or Underwriters by you and the Company as provided in subsection (a) above,
the aggregate number of such Securities which remains unpurchased does not exceed one eleventh of
the aggregate number of all the Securities to be purchased, then the Company shall have the right
to require each non-defaulting Underwriter to purchase the number of shares which such Underwriter
agreed to purchase hereunder at such Time of Delivery and, in addition, to require each
non-defaulting Underwriter to purchase its pro rata share (based on the number of Securities which
such Underwriter agreed to purchase hereunder) of the Securities of such defaulting Underwriter or
Underwriters for which such arrangements have not been made; but nothing herein shall relieve a
defaulting Underwriter from liability for its default.



(c) If, after giving effect to any arrangements for the purchase of the Securities of a
defaulting Underwriter or Underwriters by you and the Company as provided in subsection (a) above,
the aggregate number of such Securities which remains unpurchased exceeds one eleventh of the
aggregate number of all the Securities to be purchased at such Time of Delivery, or if the Company
shall not exercise the right described in subsection (b) above to require non-defaulting
Underwriters to purchase Securities of a defaulting Underwriter or Underwriters, then this
Agreement (or, with respect to the Second Time of Delivery, the obligations of the Underwriters to
purchase and of the Company to sell the Optional Securities) shall thereupon terminate, without
liability on the part of any non-defaulting Underwriter or the Company, except for the expenses to
be borne by the Company and the Underwriters as provided in Section 7 hereof and the indemnity and
contribution agreements in Section 9 hereof; but nothing herein shall relieve a defaulting
Underwriter from liability for its default.



11. The respective indemnities, agreements, representations, warranties and other statements
of the Company and the several Underwriters, as set forth in this Agreement or made by or on behalf
of them, respectively, pursuant to this Agreement, shall remain in full force and effect,
regardless of any investigation (or any statement as to the results thereof) made by or on behalf
of any Underwriter or any controlling person of any Underwriter, or the Company, or any officer or
director or controlling person of the Company, and shall survive delivery of and payment for the
Securities.



12. If this Agreement shall be terminated pursuant to Section 10 hereof, the Company shall not
then be under any liability to any Underwriter except as provided in Sections 7 and 9 hereof; but,
if for any other reason, the Securities are not delivered by or on behalf of the Company as
provided herein, the Company will reimburse the Underwriters through you for all out of pocket
expenses approved in writing by you, including fees and disbursements of counsel, reasonably
incurred by the Underwriters in making preparations for the purchase, sale and delivery of the
Securities, but the Company shall then be under no further liability to any Underwriter except as
provided in Sections 7 and 9 hereof.



13. In all dealings hereunder, you shall act on behalf of each of the Underwriters, and the
parties hereto shall be entitled to act and rely upon any statement, request, notice or agreement
on behalf of any Underwriter made or given by you jointly as Representatives or by Goldman, Sachs &
Co. on behalf of you as the Representatives.



All statements, requests, notices and agreements hereunder shall be in writing, and if to the
Underwriters shall be delivered or sent by mail or facsimile transmission to you as the
representatives in care of Goldman, Sachs & Co., 85 Broad Street, 23rd Floor, New York, New York
10004, Attention: Registration Department; and if to the Company shall be delivered or sent by
mail, telex or facsimile transmission to the address of the Company set forth in the Registration
Statement, Attention: Secretary; with a copy to Latham & Watkins LLP, 555 Eleventh Street, NW,
Suite 1000, Washington, DC 20004, Attention: Scott C. Herlihy, facsimile number (202) 637-2201;
provided, however, that any notice to an Underwriter pursuant to Section 9(c) hereof shall be
delivered or sent by mail, telex or facsimile transmission to such Underwriter at its address set
forth in its Underwriters’ Questionnaire which address will be supplied to the Company by you upon
request. Any such statements, requests, notices or agreements shall take effect upon receipt
thereof.



In accordance with the requirements of the USA Patriot Act (Title III of Pub. L. 107-56
(signed into law October 26, 2001)), the underwriters are required to obtain, verify and record
information that identifies their respective clients, including the Company, which information may
include the name and address of their respective clients, as well as other information that will
allow the underwriters to properly identify their respective clients.



14. This Agreement shall be binding upon, and inure solely to the benefit of, the
Underwriters, the Company and, to the extent provided in Sections 9 and 11 hereof, the officers and
directors of the Company and each person who controls the Company or any Underwriter, and their
respective heirs, executors, administrators, successors and assigns, and no other person shall
acquire or have any right under or by virtue of this Agreement. No purchaser of any of the
Securities from any Underwriter shall be deemed a successor or assign by reason merely of such
purchase.



15. Time shall be of the essence of this Agreement. As used herein, the term “business day”
shall mean any day when the Commission’s office in Washington, D.C. is open for business.



16. The Company acknowledges and agrees that (i) the purchase and sale of the Securities
pursuant to this Agreement is an arm’s-length commercial transaction between the Company, on the
one hand, and the several Underwriters, on the other, (ii) in connection therewith and with the
process leading to such transaction each Underwriter is acting solely as a principal and not the
agent or fiduciary of the Company, (iii) no Underwriter has assumed an advisory or fiduciary
responsibility in favor of the Company with respect to the offering contemplated hereby or the
process leading thereto (irrespective of whether such Underwriter has advised or is currently
advising the Company on other matters) or any other obligation to the Company except the
obligations expressly set forth in this Agreement and (iv) the Company has consulted its own legal
and financial advisors to the extent it deemed appropriate. The Company agrees that it will not
claim that the Underwriters, or any of them, has rendered advisory services of any nature or
respect, or owes a fiduciary or similar duty to the Company, in connection with such transaction or
the process leading thereto.



17. This Agreement supersedes all prior agreements and understandings (whether written or
oral) between the Company and the Underwriters, or any of them, with respect to the subject matter
hereof.



18. This Agreement shall be governed by and construed in accordance with the laws of the State
of New York.



19. The Company and each of the Underwriters hereby irrevocably waives, to the fullest extent
permitted by applicable law, any and all right to trial by jury in any legal proceeding arising out
of or relating to this Agreement or the transactions contemplated hereby.



20. This Agreement may be executed by any one or more of the parties hereto in any number of
counterparts, each of which shall be deemed to be an original, but all such respective counterparts
shall together constitute one and the same instrument.



21. Notwithstanding anything herein to the contrary, the Company (and the Company’s employees,
representatives and other agents) are authorized to disclose to any persons the U.S. federal and
state income tax treatment and tax structure of the potential transaction and all materials of any
kind (including tax opinions and other tax analyses) provided to the Company relating to that
treatment and structure, without the Underwriters’ imposing any limitation of any kind. However,
any information relating to the tax treatment and tax structure shall remain confidential (and the
foregoing sentence shall not apply) to the extent necessary to enable any person to comply with
securities laws. For this purpose, “tax structure” is limited to any facts that may be relevant to
that treatment.



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If the foregoing is in accordance with your understanding, please sign and return to us five
counterparts hereof, and upon the acceptance hereof by you, on behalf of each of the Underwriters,
this letter and such acceptance hereof shall constitute a binding agreement between each of the
Underwriters and the Company. It is understood that your acceptance of this letter on behalf of
each of the Underwriters is pursuant to the authority set forth in a form of Agreement among
Underwriters, the form of which shall be submitted to the Company for examination upon request, but
without warranty on your part as to the authority of the signers thereof.




Very truly yours,




USEC Inc.



	 	 	 
	By:

	 	/s/ John C. Barpoulis
	
 
	 	 
	
 
	 	Name: John C. Barpoulis

Title: Senior Vice President &

Chief Financial Officer






Accepted as of the date hereof on



behalf of each of the Underwriters:



Goldman, Sachs & Co.



By: /s/ Goldman, Sachs & Co.



(Goldman, Sachs & Co.)

Merrill Lynch, Pierce, Fenner & Smith




	 	 	Incorporated





By:/s/ Jeff Kulik

Name: Jeff Kulik

Title: Managing Director




	 	 	 	 	 	 	 	 	 
	SCHEDULE I	 	 	 	 	 	 
	 	 	 	 	 	 	Number of Optional
	 	 	 	 	 	 	Securities to be
	 	 	Total Number of	 	Purchased if
	 	 	Firm Securities	 	Maximum Option
	 	 	to be Purchased	 	Exercised
	Underwriter	 	 	 	 	 	 	 	 
	Goldman, Sachs & Co.
	 	 	8,600,000	 	 	 	1,290,000	 
	Merrill Lynch, Pierce, Fenner & Smith
Incorporated
	 	 	5,600,000	 	 	 	840,000	 
	Wachovia Capital Markets, LLC
	 	 	3,100,000	 	 	 	465,000	 
	Jefferies & Company, Inc.
	 	 	1,350,000	 	 	 	202,500	 
	Natexis Bleichroeder Inc.
	 	 	1,350,000	 	 	 	202,500	 
	Total
	 	 	20,000,000	 	 	 	23,000,000	 






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SCHEDULE II




(a) Issuer Free Writing Prospectuses Not Included in the Pricing Disclosure Package:



(i) Press Release, dated September 14, 2007



(ii) Electronic Roadshow



(iii) Press Release, dated September 24, 2007



(b) Issuer Free Writing Prospectuses Included in the Pricing Disclosure Package:



(i) Pricing Term Sheet



(c) Additional Documents Incorporated by Reference:




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