<PAGE>
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OMB APPROVAL
UNITED STATES OMB NUMBER 3235-0145
SECURITIES AND EXCHANGE COMMISSION EXPIRES: DECEMBER 31, 1999
WASHINGTON, D.C. 20549 ESTIMATED AVERAGE BURDEN
HOURS PER RESPONSE . . . 14.90
--------------------------------
SCHEDULE 13G
UNDER THE SECURITIES EXCHANGE ACT OF 1934
(AMENDMENT NO. ____)*
Union Pacific Resources Group Inc
- --------------------------------------------------------------------------------
(Name of Issuer)
Common
- --------------------------------------------------------------------------------
(Title of Class of Securities)
907834105
-------------------------------------------
(CUSIP Number)
Check the following box if a fee is being paid with this statement [_]. (A fee
is not required only if the filing person: (1) has a previous statement on file
reporting beneficial ownership of more than five percent of the class of
securities described in Item 1; and (2) has filed no amendment subsequent
thereto reporting beneficial ownership of five percent or less of such class.)
(See Rule 13d-7).
*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 that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).
PAGE 1 OF 4 PAGES
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CUSIP NO. 907834105 13G PAGE 2 OF 4 PAGES
- ----------------------- ---------------------
- ------------------------------------------------------------------------------
NAME OF REPORTING PERSON
1 S.S. or I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
Dodge & Cox 94-1441975
- ------------------------------------------------------------------------------
CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
2 (a) [_]
(b) [_]
N/A
- ------------------------------------------------------------------------------
SEC USE ONLY
3
- ------------------------------------------------------------------------------
CITIZENSHIP OR PLACE OF ORGANIZATION
4
California - U.S.A
- ------------------------------------------------------------------------------
SOLE VOTING POWER
5
NUMBER OF
13,806,732
SHARES -----------------------------------------------------------
SHARED VOTING POWER
BENEFICIALLY 6
OWNED BY 187,363
-----------------------------------------------------------
EACH SOLE DISPOSITIVE POWER
7
REPORTING
15,317,803
PERSON -----------------------------------------------------------
SHARED DISPOSITIVE POWER
WITH 8
-0-
- ------------------------------------------------------------------------------
AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
9
15,317,803
- ------------------------------------------------------------------------------
CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*
10
[_]
N/A
- ------------------------------------------------------------------------------
PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
11
6.1%
- ------------------------------------------------------------------------------
TYPE OF REPORTING PERSON*
12
IA
- ------------------------------------------------------------------------------
*SEE INSTRUCTIONS BEFORE FILLING OUT!
PAGE 2 OF 4 PAGES
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Item 1(a) Name of Issuer:
--------------
Union Pacific Resources Group
Item 1(b) Address of Issuer's Principal Executive Offices:
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801 Cherry Street
Fort Worth, Texas 76102-6803
Item 2(a) Name of Person Filing:
---------------------
Dodge & Cox
Item 2(b) Address of the Principal Office or, if none, Residence:
-------------------------------------------------------
One Sansome St., 35th Floor
San Francisco, CA 94104
Item 2(c) Citizenship:
-----------
California - U.S.A.
Item 2(d) Title of Class of Securities:
----------------------------
Common
Item 2(e) CUSIP Number:
------------
907834105
Item 3 If the Statement is being filed pursuant to Rule 13d-1(b),
----------------------------------------------------------
or 13d-2(b), check whether the person filing is a:
-------------------------------------------------
(e) [X] Investment Advisor registered under section 203 of
the Investment Advisors Act of 1940
Item 4 Ownership:
---------
(a) Amount Beneficially Owned:
-------------------------
15,317,803
(b) Percent of Class:
----------------
6.1%
PAGE 3 OF 4 PAGES
<PAGE>
(c) Number of shares as to which such person has:
---------------------------------------------
(i) sole power to vote or direct the vote: 13,806,732
(ii) shared power to vote or direct the vote: 187,363
(iii) sole power to dispose or to direct the disposition of:
15,317,803
(iv) shared power to dispose or to direct the
disposition of: -0-
Item 5 Ownership of Five Percent or Less of a Class:
--------------------------------------------
Not applicable.
Item 6 Ownership of More than Five Percent on Behalf of Another
--------------------------------------------------------
Person:
------
Securities reported on this Schedule 13G are beneficially owned by
clients of Dodge & Cox, which clients may include investment
companies registered under the Investment Company Act and/or
employee benefit plans, pension funds, endowment funds or other
institutional clients.
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 a Group:
--------------------------------
Not applicable.
Item 10 Certification:
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By signing below I certify that, to the best of my knowledge and
belief, the securities referred to above were acquired in the
ordinary course of business and were not acquired for the purpose
of and do not have the effect of changing or influencing the
control of the issuer of such securities and were not acquired in
connection with or as a participant in any transaction having such
purpose or effect.
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.
Dated: February 10, 1999
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DODGE & COX
By: /s/ W. Timothy Ryan
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Name: W. Timothy Ryan
-------------------------------------
Title: Senior Vice President
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PAGE 4 OF 4 PAGES
