UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                 SCHEDULE 13G/A

                    Under the Securities Exchange Act of 1934
                               (Amendment No. 1)*

                         UNITED THERAPEUTICS CORPORATION
        -----------------------------------------------------------------
                                (Name of Issuer)

                                  Common Stock
        -----------------------------------------------------------------
                         (Title of Class of Securities)

                                    91307C102
                              --------------------
                                 (CUSIP Number)

                                December 31, 2002
        ----------------------------------------------------------------
             (Date of Event Which Requires Filing of this Statement)

Check the  appropriate box to designate the rule pursuant to which this Schedule
is filed:

         / X /    Rule 13d-1(b)
         /   /    Rule 13d-1(c)
         /   /    Rule 13d-1(d)

*The  remainder of this cover page shall be filled out for a reporting  person's
initial filing on this form with respect to the subject class of securities, and
for any  subsequent  amendment  containing  information  which  would  alter the
disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the  Securities  Exchange  Act of
1934 ("Act") or otherwise  subject to the  liabilities of the section of the Act
but  shall be  subject  to all other  provisions  of the Act  (however,  see the
Notes).








                                  SCHEDULE 13G
                              CUSIP NO. 91307C102

1.   Names of Reporting  Persons.  I.R.S.  Identification  Nos. of above persons
     (entities only).

     Quaker Capital Management Corporation
     --------------------------------------------------------------------------

2.   Check the Appropriate Box if a Member of a Group

     (a)
              ------
     (b)        X
              ------

3.   SEC Use Only
                    -----------------------------------------------------------

4.   Citizenship or Place of Organization                      Pennsylvania
                                                               ----------------

Number of         5.       Sole Voting Power                   336,300
  Shares                                                       ----------------
Beneficially      6.       Shared Voting Power                 665,250
  Owned by                                                     ----------------
Each Reporting    7.       Sole Dispositive Power              336,300
    Person                                                     ----------------
         With:    8.       Shared Dispositive Power            665,250
                                                               ----------------

9.   Aggregate Amount Beneficially Owned by Each Reporting Person

     1,001,550
     ----------------

10.  Check if the Aggregate  Amount in Row (9) Excludes
     Certain Shares
                      --------

     The Reporting Person disclaims beneficial ownership of 999,050 shares owned
     by its clients.

11.  Percent of Class Represented by Amount in Row (9)

                                                   4.79%
                                                   --------

12.  Type of Reporting Person                           IA
                                                   --------------



                                  Page 2 of 7



                                  SCHEDULE 13G
                              CUSIP NO. 91307C102

Item 1.

     (a)  Name of Issuer

          UNITED THERAPEUTICS CORPORATION
          ---------------------------------------------------------------------

     (b)  Address of Issuer's Principal Executive Offices

          1110 Spring Street, Silver Spring, MD 20910
          ---------------------------------------------------------------------
Item 2.

     (a)  Name of Persons Filing

          Quaker Capital Management Corporation
          ---------------------------------------------------------------------

     (b)  Address of Principal Business Office or, if none, Residence

          401 Wood Street, Suite 1300, Pittsburgh, PA  15222
          ---------------------------------------------------------------------

     (c)  Citizenship

          Pennsylvania, USA
          ---------------------------------------------------------------------

     (d)  Title of Class of Securities

          Common Stock
          ---------------------------------------------------------------------

     (e)  CUSIP Number

          91307C102
          ---------------------------------------------------------------------



                                  Page 3 of 7



                                  SCHEDULE 13G
                               CUSIP NO. 9137C102

Item 3. If this statement is filed pursuant toss.ss.240.13d-1(b) or 240.13d-2(b)
        or (c), check whether the person filing is a:

  (a)  /   /   Broker of dealer registered under section 15 of
               the Act;

  (b)  /   /   Bank as defined in section 3(a)(6) of the Act;

  (c)  /   /   Insurance company as defined in section 3(a)(19) of the Act;

  (d)  /   /   Investment company registered under section 8 of the Investment
               Company Act of 1940;

  (e)  / X /   An investment adviser in accordance withss.240.13d-
               1(b)(l)(ii)(E);

  (f)  /   /   An employee benefit plan or endowment fund in accordance
               withss.240.13d-1(b)(1)(ii)(F);

  (g)  /   /   A parent holding company or control person in accordance
               withss.240.13d-1(b)(1)(ii)(G);

  (h)  /   /   A savings association as defined in Section 3(b) of the Federal
               Deposit Insurance Act;

  (i)  /   /   A church plan that is excluded from the definition of an
               investment company under section 3(c)(14) of the Investment
               Company Act of 1940;

  (j)  /   /   Group, in accordance withss.240.13d-1((b)(l)(ii)(J)

Item 4. Ownership
        ---------

     (a)  The Reporting  Person, in its capacity as investment  adviser,  may be
          deemed to be the  beneficial  owner of  999,050  shares of the  Common
          Stock of the  Issuer  which are owned by various  investment  advisory
          clients of the  Reporting  Person in accounts over which the Reporting
          Person has  discretionary  authority.  The filing of this report shall
          not be  construed as an admission  that the  Reporting  Person is, for
          purposes of Section 13(d) or 13(g) of the Act, the beneficial owner of
          these  securities.  Additionally,  the  Reporting  Person  and/or  its
          principals  and  employees own 2,500 shares of the Common Stock of the
          Issuer.


                                  Page 4 of 7



                                  SCHEDULE 13G
                              CUSIP NO. 91307C102

     (b)  The shares covered by this report  represent 4.79% of the Common Stock
          of the Issuer.

     (c)  The  Reporting  Person has shared  voting and  dispositive  power over
          665,250  shares and sole  voting and  dispositive  power over  333,800
          shares  owned by its clients  and held in  accounts  over which it has
          discretionary  authority.  The Reporting  Person and/or its principals
          and employees  have sole voting and  dispositive  power over the 2,500
          shares  owned  by the  Reporting  Person  and/or  its  principals  and
          employees.

Item 5.   Ownership of Five Percent or Less of a Class

          If this statement is being filed to report the fact that as of the
date hereof,  the reporting  person has ceased to be the beneficial owner of
more than five percent of the class of securities, check the following:    X
                                                                        -------

Item 6.  Ownership of More than Five Percent on Behalf of Another Person

         999,050 of the  shares  with  respect to which this  report is filed
are owned by a variety of  investment  advisory  clients of the  Reporting
Person, which clients are entitled to receive dividends on and the proceeds from
the sale of such shares. No client is known to own more than 5% of the class.

Item 7.  Identification and Classification of the Subsidiary Which Acquired the
         Security Being Reported on by the Parent Holding Company

         Not applicable.

Item 8.  Identification and Classification of Members of the Group

         Not applicable.

Item 9.  Notice of Dissolution of Group

         Not applicable.

Item 10. Certification

         By signing  below I certify  that, to the best of my knowledge and
belief,  the securities  referred to above were acquired and are held in the
ordinary  course  of  business  and were not  acquired  and are not held for the


                                  Page 5 of 7



                                  SCHEDULE 13G
                              CUSIP NO. 91307C102

purpose of or with the effect of  changing  or  influencing  the  control of the
issuer of the  securities  and were not acquired and are not held in  connection
with or as a participant in any transaction having that purpose or effect.





                                  Page 6 of 7



                                  SCHEDULE 13G
                              CUSIP NO. 91307C102

                                    SIGNATURE

         After  reasonable  inquiry and to the best of my knowledge and belief,
I certify  that the  information  set forth in this  statement is true, complete
 and correct.


                                 QUAKER CAPITAL MANAGEMENT CORPORATION


                                      FEBRUARY 13, 2003
                                      -----------------------------------
                                                     Date


                                      /S/  MARK G. SCHOEPPNER
                                      -----------------------------------
                                                   Signature


                                      MARK G. SCHOEPPNER, PRESIDENT
                                      -----------------------------------
                                                  Name/Title


                                  Page 7 of 7