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

                                 SCHEDULE 13G/A
                    Under the Securities Exchange Act of 1934
                                (Amendment No. 2)

                               Noble Corporation
                               (Name of Issuer)

                                  Common Stock
                         (Title of Class of Securities)

                                   H5833N103
                                 (CUSIP Number)

                               December 31, 2011
             (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 that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).




                               CUSIP No. H5833N103


       1.    Names of Reporting Person

             Wentworth, Hauser & Violich, Inc.

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

             [ ] (a)
             [ ] (b)

       3.    SEC Use Only

       4.    Citizenship or Place of Organization

             Washington, United States

       		 5.  Sole Voting Power:  15,249,864
Number of
Shares           6.  Shared Voting Power: 0
Beneficially
Owned by         7.  Sole Dispositive Power:  0
Each Reporting
Person With      8.  Shared Dispositive Power:  16,130,954

       9.    Aggregate Amount Beneficially Owned by Each Reporting Person

             16,130,954

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

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

	     6.39%

       12.   Type of Reporting Person

	     IA





 			       CUSIP No. H5833N103


       1.    Names of Reporting Person

             Hirayama Investments, LLC

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

             [ ] (a)
             [ ] (b)

       3.    SEC Use Only

       4.    Citizenship or Place of Organization

             Delaware, United States

       		 5.  Sole Voting Power: 0
Number of
Shares           6.  Shared Voting Power: 0
Beneficially
Owned by         7.  Sole Dispositive Power:  0
Each Reporting
Person With      8.  Shared Dispositive Power:  16,130,954

       9.    Aggregate Amount Beneficially Owned by Each Reporting Person

             16,130,954

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

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

	     6.39%

       12.   Type of Reporting Person

	     IA




Item 1. (a)  Name of Issuer: Noble Corporation

        (b)  Address of Issuer's Principal Executive Offices:

             Dorfstrasse 19A
             Baar, Switzerland 6340

Item 2. (a)  Name of Person Filing:

             Wentworth, Hauser & Violich, Inc. ("Wentworth")
	     Hirayama Investments, LLC ("Hirayama")

        (b)  Address of Principal Business Offices:

	     Wentworth, Hauser & Violich, Inc.
	     301 Battery Street, Suite 400
	     San Francisco, CA  94111-3203
	     United States

	     Hirayama Investments, LLC
	     301 Battery Street, Suite 400
	     San Francisco, CA  94111-3203
	     United States

        (c)  Citizenship:

             Please refer to Item 4 on each cover sheet for each filing person.

        (d)  Title of Class of Securities

             Common Stock

        (e)  CUSIP Number: H5833N103

Item 3.  Wentworth, Hauser & Violich, Inc. is an investment adviser in
	 accordance with 13d-1(b)(1)(ii)(E); Hirayama Investments, LLC
	 is an investment adviser in accordance with 13d-1(b)(1)(ii)(E);

Item 4.  Ownership

         Please see Items 5 - 9 and 11 on each cover sheet for each filing
         person.

	 Under the definition of "beneficial ownership" in Rule 13d-3 under
	 the Securities Exchange Act of 1934, it is also possible that the
	 individual directors, executive officers, and/or shareholders of
	 Wentworth and/or Hirayama might be deemed the "beneficial owners"
	 of some or all of the securities to which this Schedule 13G/A relates
	 in that they might be deemed to share the power to direct the voting
	 or disposition of such securities.  Neither the filing of this
	 Schedule 13G/A nor any of its contents shall be deemed to constitute an
	 admission that any of such individuals is, for any purpose, the
	 beneficial owner of any of the securities to which this Schedule 13G/A
	 relates, and such beneficial ownership is expressly disclaimed.

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

	 Not Applicable




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 held in the ordinary
course of business and were not acquired and are not held for the 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.





                               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.

Date: February 14, 2012
                                       Wentworth, Hauser & Violich, Inc.

                                       By: /s/ Pavita Fleischer
                                       --------------------------
                                       Name: Pavita Fleischer
                                       Title: Chief Compliance Officer

				       Hirayama Investments, LLC

                                       By: /s/ Richard K. Hirayama
                                       --------------------------
                                       Name: Richard K. Hirayama
                                       Title: Managing Member



 			JOINT FILING AGREEMENT

The undersigned hereby agree that the Statement on this Schedule 13G/A, dated
February 14, 2012, with respect to the Common Stock of Noble Corporation.
is filed on behalf of each of us pursuant to and in accordance with the
provisions of Rule 13d-1(k) under the Securities Exchange Act of 1934, as
amended, and that this Agreement shall be included as an Exhibit to this
Schedule 13G/A. Each of the undersigned agrees to be responsible for the timely
filing of the Schedule 13G/A, and for the completeness and accuracy of the
information concerning itself contained therein. This Agreement may be
executed in any number of counterparts, all of which taken together shall
constitute one and the same instrument.

        IN WITNESS WHEREOF, the undersigned have executed this Agreement as of
the 14th day of February 2012.

Date: February 14, 2012
                                       Wentworth, Hauser & Violich, Inc.

                                       By: /s/ Pavita Fleischer
                                       --------------------------
                                       Name: Pavita Fleischer
                                       Title: Chief Compliance Officer

				       Hirayama Investments, LLC

                                       By: /s/ Richard K. Hirayama
                                       --------------------------
                                       Name: Richard K. Hirayama
                                       Title: Managing Member