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As filed with the U.S. Securities and Exchange Commission on March 19, 2004

Registration No. 333-12008



SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549


POST-EFFECTIVE AMENDMENT TO
FORM F-6
REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933
For Depositary Shares Evidenced by American Depositary Receipts


MOBILE TELESYSTEMS OJSC
(Exact name of issuer of deposited securities as specified in its charter)

Not applicable
(Translation of issuer's name into English)

RUSSIAN FEDERATION
(Jurisdiction of incorporation or organization of issuer)

JPMORGAN CHASE BANK
(Exact name of depositary as specified in its charter)

4 New York Plaza, New York, NY 10004
Telephone (212) 623-0636
(Address, including zip code, and telephone number, including area code, of depositary's principal executive offices)


Puglisi & Associates
850 Library Avenue, Suite 204
Newark, Delaware 19711
(302) 738-6680
(Address, including zip code, and telephone number, including area code, of agent for service)

Copy to:

Scott A. Ziegler, Esq.
Ziegler, Ziegler & Associates LLP
570 Lexington Avenue, 44th Floor
New York, New York 10022
(212) 319-7600

        It is proposed that this filing become effective under Rule 466


        If a separate registration statement has been filed to register the deposited shares, check the following box. o


CALCULATION OF REGISTRATION FEE


Title of each class of
Securities to be registered

  Amount
To be registered

  Proposed maximum
aggregate price
per unit(1)

  Proposed maximum
aggregate offering
price(2)

  Amount of
registration fee


American Depositary Shares evidenced by American Depositary Receipts, each American Depositary Share representing twenty ordinary shares of Mobile Telesystems OJSC   N/A   N/A   N/A   N/A





PART I
INFORMATION REQUIRED IN PROSPECTUS

        The Prospectus consists of the proposed form of American Depositary Receipt ("ADR" or "American Depositary Receipt") included as Exhibit A to the Amendment No. 1 to Deposit Agreement filed as Exhibit (a)(2) to this Post-Effective Amendment No. 1 to the Registration Statement, which is incorporated herein by reference.


CROSS REFERENCE SHEET

Item 1. DESCRIPTION OF SECURITIES TO BE REGISTERED

Item Number and Caption

  Location in Form of American Depositary
Receipt Filed Herewith as Prospectus

(1)   Name and address of Depositary   Introductory paragraph
(2)   Title of American Depositary Receipts and identity of deposited securities   Face of American Depositary Receipt, top center
    Terms of Deposit:    
    (i)   Amount of deposited securities represented by one unit of American Depositary Shares   Face of American Depositary Receipt, upper right corner
    (ii)   Procedure for voting, if any, the deposited securities   Paragraphs (6), (12) and (13)
    (iii)   Collection and distribution of dividends   Paragraphs (4), (5), (7), (11), (12) and (14)
    (iv)   Transmission of notices, reports and proxy soliciting material   Paragraphs (4), (9), (12) and (13)
    (v)   Sale or exercise of rights   Paragraphs (4), (5), (7) and (11)
    (vi)   Deposit or sale of securities resulting from dividends, splits or plans of reorganization   Paragraphs (4), (5), (7), (11), (12) and (14)
    (vii)   Amendment, extension or termination of the Deposit Agreement   Paragraphs (17) and (18)
    (viii)   Rights of holders of receipts to inspect the transfer books of the Depositary and the list of Holders of receipts   Paragraph (3)
    (ix)   Restrictions upon the right to deposit or withdraw the underlying securities   Paragraphs (1), (2), (4), (5) and (6)
    (x)   Limitation upon the liability of the Depositary   Paragraphs (15), (18) and (20)
(3)   Fees and Charges   Paragraph (7)

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Item 2. AVAILABLE INFORMATION

Item Number and Caption

  Location in Form of American Depositary
Receipt Filed Herewith as Prospectus

(b)   Statement that Mobile Telesystems OJSC is subject to the periodic reporting requirements of the Securities Exchange Act of 1934, and accordingly, files certain reports with the Commission and that such reports can be inspected by holders of American Depositary Receipts and copied at public reference facilities maintained by the Commission in Washington, D.C.   Paragraph (9)

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PART II
INFORMATION NOT REQUIRED IN PROSPECTUS

Item 3. EXHIBITS

(a)(1)   Deposit Agreement. Form of Deposit Agreement dated as of July 6, 2000 among Mobile Telesystems OJSC (the "Company"), JPMorgan Chase Bank (fka Morgan Guaranty Trust Company of New York), as depositary (the "Depositary"), and all holders from time to time of ADRs issued thereunder (the "Deposit Agreement"). Previously filed as Exhibit (a) to Registration Statement on Form F-6 (333-12008) filed with the Securities and Exchange Commission, which is incorporated herein by reference.

(a)(2)

 

Amendment to Deposit Agreement. Form of Amendment No. 1 to Deposit Agreement, including the form of ADR, is filed herewith as Exhibit (a)(2).

(b)

 

Any other agreement to which the Depositary is a party relating to the issuance of the American Depositary Shares registered hereunder or the custody of the deposited securities represented thereby. Not applicable.

(c)

 

Every material contract relating to the deposited securities between the Depositary and the issuer of the deposited securities in effect at any time within the last three years. Not applicable.

(d)

 

Opinion of counsel to the Depositary as to the legality of the securities being registered. Previously filed as exhibit (d) to Registration Statement 333-12008 which is incorporated herein by reference.

(e)

 

Certification under Rule 466. Filed herewith as Exhibit (e).

(f)

 

Power of Attorney. Included as part of the signature pages hereto.

Item 4. UNDERTAKINGS

(a)   The Depositary hereby undertakes to make available at the principal office of the Depositary in the United States, for inspection by holders of the American Depositary Receipts, any reports and communications received from the issuer of the deposited securities which are both (1) received by the Depositary as the holder of the deposited securities, and (2) made generally available to the holders of the underlying securities by the issuer.

(b)

 

If the amounts of fees charged are not disclosed in the prospectus, the Depositary undertakes to prepare a separate document stating the amount of any fee charged and describing the service for which it is charged and to deliver promptly a copy of such fee schedule without charge to anyone upon request. The Depositary undertakes to notify each registered holder of an American Depositary Receipt thirty days before any change in the fee schedule.

4



SIGNATURE

        Pursuant to the requirements of the Securities Act of 1933, the registrant certifies that it has reasonable grounds to believe that all the requirements for filing on Form F-6 are met and has duly caused this Post-Effective Amendment to Registration Statement on Form F-6 to be signed on its behalf by the undersigned, thereunto duly authorized, in The City of New York, State of New York, on March 19, 2004.

    Legal entity created by the form of Deposit Agreement for the issuance of ADRs evidencing American Depositary Shares

 

 

By: JPMORGAN CHASE BANK, as Depositary

 

 

By:

 

/s/  
JOSEPH M. LEINHAUSER      
    Name:   Joseph M. Leinhauser
    Title:   Vice President

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SIGNATURES

        Pursuant to the requirements of the Securities Act of 1933, Mobile Telesystems OJSC certifies that it has reasonable grounds to believe that all the requirements for filing on Form F-6 are met and has duly caused this Post-Effective Amendment No. 1 to Registration Statement on Form F-6 to be signed on its behalf by the undersigned, thereunto duly authorized, in Moscow, Russian Federation, on March 18, 2004.

    MOBILE TELESYSTEMS OJSC

 

 

By:

 

/s/  
VASSILY V. SIDOROV      
    Name:   Vassily V. Sidorov
    Title:   President


POWER OF ATTORNEY

        KNOW ALL MEN BY THESE PRESENTS, that each person whose signature appears below hereby constitutes and appoints Vassily V. Sidorov his true and lawful attorney-in-fact and agent, with full power of substitution and resubstitution, for him and in his name, place and stead, in any and all capacities, to sign any and all amendments (including pre-effective and post-effective amendments) to this Registration Statement, and to file the same, with all exhibits thereto, and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorney-in-fact and agent full power and authority to do and perform each and every act and thing requisite and necessary to be done in and about the premises, as fully to all intents and purposes as he might or could do in person, hereby ratifying and confirming all that said attorney-in-fact and agent, or his substitute or substitutes, may lawfully do or cause to be done by virtue thereof.

        Pursuant to the requirements of the Securities Act of 1933, as amended, this Registration Statement has been signed by the following persons in the capacities indicated as of March 18, 2004.

Signatures

  Title

/s/  VLADIMIR LAGUTIN      
Vladimir Lagutin
  Chairman


Michael Guenther

 

Deputy Chairman

/s/  
VASSILY V. SIDOROV      
Vassily V. Sidorov

 

President


Alexei Buyanov

 

Director


Alexander Goncharuk

 

Director
     

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/s/  
MIKHAIL SMIRNOV      
Mikhail Smirnov

 

Director

/s/  
GERNOT TAUFMANN      
Gernot Taufmann

 

Director

/s/  
PAUL KUSUBOV      
Paul Kusubov

 

Director

/s/  
NIKOLAI TSEKHOMSKY      
Nikolai Tsekhomsky

 

Chief Financial Officer

/s/  
DONALD J. PUGLISI      
Donald J. Puglisi

 

Authorized Representative in the United States

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INDEX TO EXHIBITS

Exhibit Number

   
  Sequentially Numbered Page
(a)   Form of Amendment No. 1 to Deposit Agreement    
(e)   Rule 466 Certification    



QuickLinks

PART I INFORMATION REQUIRED IN PROSPECTUS
CROSS REFERENCE SHEET
PART II INFORMATION NOT REQUIRED IN PROSPECTUS
SIGNATURE
SIGNATURES
POWER OF ATTORNEY
INDEX TO EXHIBITS