e424b7
 

Filed Pursuant to Rule 424(b)(7)
Registration No. 333-142297
PROSPECTUS SUPPLEMENT NO. 4
TO PROSPECTUS DATED APRIL 23, 2007
 
UAL CORPORATION
$726,000,000
 
4.50% SENIOR LIMITED-SUBORDINATION CONVERTIBLE NOTES DUE 2021,
SHARES OF COMMON STOCK ISSUABLE UPON CONVERSION OF
THE NOTES OR IN PAYMENT OF ACCRUED INTEREST ON THE NOTES
AND RELATED GUARANTEE BY UNITED AIR LINES, INC.
 
 
This prospectus supplement No. 4 supplements the prospectus dated April 23, 2007 (including any amendments or supplements thereto, the “prospectus”) relating to the resale by selling securityholders of up to $726,000,000 aggregate principal amount of 4.50% Senior Limited-Subordination Convertible Notes due 2021 (the “notes”) and the shares of common stock of UAL Corporation (“UAL”) issuable upon conversion of the notes or in payment of accrued interest on the notes. The notes are guaranteed on an unsecured basis by United Air Lines, Inc., a wholly-owned subsidiary of UAL.
 
This prospectus supplement should be read in conjunction with the prospectus, which is to be delivered with this prospectus supplement, and this prospectus supplement is qualified by reference to the prospectus, except to the extent that the information in this prospectus supplement supersedes the information contained in the prospectus. This prospectus supplement is not complete without, and may not be delivered or utilized except in connection with, the prospectus.
 
 
Investing in the notes and UAL common stock involves risks. See “Risk Factors” beginning on page 7 of the prospectus dated April 23, 2007.
 
 
Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus supplement or prospectus is truthful or complete. Any representation to the contrary is a criminal offense.
 
 
The information appearing under the heading of the prospectus entitled “Selling Securityholders” sets forth information with respect to the selling securityholders and the respective amounts of notes beneficially owned by each selling securityholder that may be offered pursuant to the prospectus. The information set forth below supplements the information previously listed in the prospectus and the prospectus is hereby supplemented by the addition or substitution, as applicable, of the following:
 
                                 
    Principal Amount of
 		                Shares of UAL
 		 
    Notes Beneficially
 		    Percentage of
 		    Shares of UAL
 		    Common Stock
 		 
    Owned and Offered
 		    Notes
 		    Common Stock
 		    Beneficially Owned
 		 
Selling Securityholder
  Hereby(a)     Outstanding     Offered Hereby(b)     After the Offering(c)  
 
Fidelity Devonshire Trust: Fidelity Equity-Income Fund(d)
  $ 21,090,000       2.9 %     605,356       —  
Fidelity Financial Trust: Fidelity Convertible Securities Fund(d)
    10,500,000       1.4 %     301,386       —  
Variable Insurance Products Fund: Equity-Income Portfolio(d)
    8,680,000       1.2 %     249,146       —  
Fidelity Puritan Trust: Fidelity Puritan Fund(d)
    7,730,000       1.1 %     221,878       —  
Fidelity Advisor Series II: Fidelity Advisor High Income Advantage Fund(d)
    5,200,000       *     149,258       —  
Fidelity Financial Trust: Fidelity Strategic Dividend and Income Fund(d)
    2,000,000       *     57,407       19,200  
Pension Investment Committee of General Motors for General Motors Employees Domestic Group Pension Trust(e)
    1,800,000       *     51,666       —  
Fidelity Large Cap Value Fund(e)
    120,000       *     3,444       —  
J.P. Morgan Securities Inc. 
    5,935,000       *     170,355       —  
Total
  $ 63,055,000       8.7 %     1,809,896       19,200  
 
 
* Less than 1%.
 
(a) Information concerning the selling securityholders may change from time to time. Any such changed information will be set forth in prospectus supplements or amendments from time to time, if required.
 
(b) Assumes conversion of all of the selling securityholder’s notes at a conversion rate of 28.7035 shares of UAL common stock per $1,000 principal amount of the notes and a cash payment in lieu of any fractional shares. This conversion rate is subject to adjustment as described under “Description of the Notes — Conversion Rights” in the prospectus. Accordingly, the number of shares of UAL common stock may increase or decrease from time to time. Fractional shares will not be issued upon conversion of the notes.
 
(c) Reflects the number of shares of UAL common stock beneficially owned prior to the offering (excluding shares of common stock issuable upon conversion of the notes).
 
(d) The entity is either an investment company or a portfolio of an investment company registered under Section 8 of the Investment Company Act of 1940, as amended, or a private investment account advised by Fidelity Management & Research Company (“FMR Co.”). FMR Co. is a Massachusetts corporation and an investment advisor registered under Section 203 of the Investment Advisers Act of 1940, as amended, and provides investment advisory services to each of such Fidelity entities identified above, and to other registered investment companies and to certain other funds which are generally offered to a limited group of investors. FMR Co. is a wholly-owned subsidiary of FMR Corp. (“FMR”), a Delaware corporation. The holdings are as of August 7, 2007.
 
(e) Shares indicated as owned by such entity are owned directly by various private investment accounts, primarily employee benefit plans for which Fidelity Management Trust Company (“FMTC”) serves as trustee or managing agent. FMTC is a wholly-owned subsidiary of FMR and a bank as defined in Section 3(a)(6) of the Securities Exchange Act of 1934, as amended.
 
 
The date of this prospectus supplement is August 14, 2007.