SECURITIES AND EXCHANGE COMMISSION
  WASHINGTON, D.C. 20549



                                  SCHEDULE 13D*
                                 (Rule 13d-101)

             INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT
            TO RULE 13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO
                                  RULE 13d-2(a)

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

                               MARINER ENERGY INC
                                (Name of Issuer)

                              	Common stock
                         (Title of Class of Securities)

                                   56845T305
                                 (CUSIP Number)

                                Svein Tore Hansen
                            SKAGEN Funds (SKAGEN AS)
                         P.O. Box 160, N-4001 Stavanger
                     		   Norway
                                (47) 51 21 38 35
                  (Name, Address and Telephone Number of Person
                Authorized to Receive Notices and Communications)

                                  June 08, 2010
                          (Date of Event which Requires
                            Filing of This Statement)



         If the filing person has previously filed a statement on Schedule 13G
to report the acquisition that is the subject of this Schedule 13D, and is
filing this schedule because of Rule 13d-1(e), 13d-1(f) or 13d-1(g), check the
following box. [ ]

         NOTE: Schedules filed in paper format shall include a signed original
and five copies of the schedule, including all exhibits. See Rule 13d-7 for
other parties to whom copies are to be sent.

                         (Continued on following pages)

                               (Page 1 of 7 Pages)


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 disclosures provided in a prior cover page.



   The information required on 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.      56845T305           SCHEDULE 13D         PAGE 2 OF 7 PAGES


    1       NAME OF REPORTING PERSON
            I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

	SKAGEN Funds, Mutual funds managed by SKAGEN AS,ORG.NO 867 762 732


    2       CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*       (a) [ ]
                                                                    (b) [ ]

    3       SEC USE ONLY

    4       SOURCE OF FUNDS*


    5       CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDING IS REQUIRED PURSUANT
            TO ITEM 2(d) or 2(e)                                         [ ]


    6       CITIZENSHIP OR PLACE OF ORGANIZATION

            Norway

                         7      SOLE VOTING POWER

                                -0-


 NUMBER OF               8      SHARED VOTING POWER
 SHARES
BENEFICIALLY                    -0-
  OWNED BY
    EACH                 9      SOLE DISPOSITIVE POWER
 REPORTING
PERSON WITH                     -0-

                         10     SHARED DISPOSITIVE POWER

                                -0-

    11      AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH PERSON

                       	June 08, 2010      4275779


    12      CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
            CERTAIN SHARES*
                                                                        [ ]

    13      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

         		June 08, 2010      4,14 %


    14      TYPE OF REPORTING PERSON*

            IV  (Investment company)

                     * SEE INSTRUCTIONS BEFORE FILLING OUT!





CUSIP NO.     56845T305            SCHEDULE 13D       PAGE 3 OF 7 PAGES



Item 1.       Security and Issuer.

       This statement on Schedule 13D relates to the shares ("Shares")
of  Mariner Energy INC (the "Issuer").
The principal executive office of the Issuer is located at
Mariner Energy Inc., One Briar Lake Plaza, Suite 2000,
2000 West Sam Houston Parkway South Houston,USA.


Item 2.       Identity and Background.

        (a) This statement is filed by SKAGEN Funds (SKAGEN AS), a Norwegian
Investment company (the "Reporting Person").The Investment company has
eleven mutual funds under management. The shares are held for investment
purposes. The Investment Director is Kristian Falnes.

        (b) The principal business address of the Reporting Person and
the Investment Director is P.O. Box 160, N-4001 Stavanger, Norway.

        (c) The principal business of the Reporting Person and the
Investment Director is investing assets for unit holders investing in the
mutual funds under their management.

        (d) Neither the Reporting Person nor the Investment Director
has,during the last five years, been convicted in a criminal proceeding
(excluding trafficviolations or similar misdemeanors).

        (e) Neither the Reporting Person nor the Investment Director has,
during the last five years, been a party to a civil proceeding of a
judicial or administrative body of competent jurisdiction and as a result
of such proceeding was or is subject to a judgment, decree or final order
enjoining future violations of, or prohibiting or mandating activities
subject to, federal or state securities laws or finding any violation
with respect to such laws.

        (f) The Reporting Person is a limited liability investment
company organized in Norway. The Investment Director and the rest of the
Principals are citizens of Norway.





CUSIP NO.     56845T305               SCHEDULE 13D     	 PAGE 4 OF 7 PAGES



Item 3.       Source and Amount of Funds or Other Consideration.

     The Shares beneficially owned by the Reporting Person were acquired
with investment funds in the mutual funds under management.



Item 4       Purpose of Transaction.

       The Reporting Person acquired the Shares for investment in the
ordinary course of business.

       Except as set forth herein, neither the Reporting Person nor the
Investment Director have any present plan or proposal that would relate to
or result in any of the matters set forth in subparagraphs (a) - (j) of
Item 4 of Schedule 13D. The Reporting Person intends to review its investment
in the Issuer on a continuing basis. Depending on various factors including,
without limitation,the Issuer's financial position and strategic direction,
price levels of the Shares, conditions in the securities market and general
economic and industry conditions, the Reporting Person may in the future take
such actions with respect to its investment in the Issuer as it deems
appropriate including,without limitation, purchasing additional Shares or
selling some or all of its Shares, and, alone or with others, pursuing
discussions with the Issuer, other stockholders and third parties with regard
to its investment in the Issuer,and/or otherwise changing its intention with
respect to any and all matters referred to in Item 4 of Schedule 13D.


Item 5.       Interest in Securities of the Company.

        (a) The aggregate percentage of Shares reported to be beneficially
owned by the Reporting Person is based upon the total of 103,211M common stocks
outstanding, registered at Bloomberg June 08, 2010.

       As of the close of business on June 08, 2010, the Reporting
Person beneficially owned 4,14 % of the shares outstanding.






CUSIP NO.     56845T305          SCHEDULE 13D         PAGE 5 OF 7 PAGES



        (b) The Reporting Person voting and dispositive powers over more than
5 % of the Shares, which powers are exercised by the Investment Director.
(See details in (C) below)

        (c) Information concerning transactions in the Shares effected by the
Reporting Person during the past sixty days is:



Trade		Settle
Date		Date		Quantity

13.04.2010	16.04.2010	19000
14.04.2010	19.04.2010	2000
27.04.2010	30.04.2010	2900
29.04.2010	04.05.2010	40000
04.05.2010	07.05.2010	2000
07.06.2010	10.06.2010	354286
07.06.2010	10.06.2010	141071
07.06.2010	10.06.2010	4643
08.06.2010	11.06.2010	779429
08.06.2010	11.06.2010	310357
08.06.2010	11.06.2010	10214




SALES:

13.04.2010	16.04.2010	19000
14.04.2010	19.04.2010	2000
27.04.2010	30.04.2010	2900
29.04.2010	04.05.2010	40000
04.05.2010	07.05.2010	2000
07.06.2010	10.06.2010	354286
07.06.2010	10.06.2010	141071
07.06.2010	10.06.2010	4643
08.06.2010	11.06.2010	779429
08.06.2010	11.06.2010	310357
08.06.2010	11.06.2010	10214



        (d) No person (other than the Reporting Person) is known to have the
right to receive or the power to direct the receipt of dividends from, or the
proceeds from the sale of, the Shares.

        (e) Not applicable.


Item 6.       Contracts, Arrangements, Understandings or Relationships with
Respect to Securities of the Company.

       Except as otherwise set forth herein, the Reporting Person does not have
any contract, arrangement, understanding or relationship with any person with
respect to any securities of the Issuer.


Item 7.       Material to be Filed as Exhibits.

Not applicable





CUSIP NO.       56845T305          SCHEDULE 13D        PAGE 6 OF 7 PAGES



                                   SIGNATURES



        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:  June 15, 2010



                            SKAGEN Funds (SKAGEN AS)
                            BY: /s/ Svein Tore Hansen

                            Name:  Svein Tore Hansen
                            Title: Business Support and Compliance

                            BY: /s/ Kristian Falnes

                            Name:  Kristian Falnes
                            Title: Investmetn Director