FORM 6-K

Special Subjects:

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

Report of Foreign Issuer
Pursuant to Rule 13a-16 or 15d-16 of
the Securities Exchange Act of 1934

For the month of December, 2005

Commission File Number 001-15092

TURKCELL ILETISIM HIZMETLERI A.S.

(Translation of registrant’s name into English)

Turkcell Plaza
Mesrutiyet Caddesi No. 153
34430 Tepebasi
Istanbul, Turkey

(Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover Form 20-F or Form 40-F

Form 20-F: ý Form 40-F: o

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1):

Note: Regulation S-T Rule 101(b)(1) only permits the submission in paper of a Form 6-K if submitted solely to provide an attached annual report to security holders.

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7):

Note: Regulation S-T Rule 101(b)(7) only permits the submission in paper of a Form 6-K if submitted to furnish a report or other document that the registrant foreign private issuer must furnish and make public under the laws of the jurisdiction in which the registrant is incorporated, domiciled or legally organized (the registrant’s “home country”), or under the rules of the home country exchange on which the registrant’s securities are traded, as long as the report or other document is not a press release, is not required to be and has not been distributed to the registrant’s security holders, and, if discussing a material event, has already been the subject of a Form 6-K submission or other Commission filing on EDGAR.

Indicate by check mark whether by furnishing the information contained in this Form, the registrant is also thereby furnishing the information to the Commission pursuant to rule 12g3-2(b) under the Securities Exchange Act of 1934.

Yes: o No: ý

If “Yes” is marked, indicate below the file number assigned to the registrant in connection with Rule 12g3-2(b) 82 —

TURKCELL PROVIDES UPDATE ON REGULATORY ENVIRONMENT

Subject: Statement made pursuant to Circular VIII, No: 39 of the Capital Markets Board.

Istanbul Stock Exchange
ISTANBUL

TURKCELL ILETISIM HIZMETLERI A.S.

Date: December 28, 2005

/s/ Muzaffer Akpinar

Name: Muzaffer Akpinar
Title: Chief Executive Officer

As we previously announced the Telecommunications Authority had designated Turkcell as an “operator holding significant market power” in the “GSM Mobile Telecommunication Services Market” and “GSM Mobil Call Termination Services Market” based on a communiqué regarding the procedures in the determination of operators holding significant market power.

As a result of the evaluation process this year and effective as of December 31, 2005 Telecommunication Authority designated other two GSM operators in Turkey as “operators holding significant market power” in the GSM mobile call termination services market along with Turkcell. As part of the same evaluation, the Telecommunications Authority also designated Turkcell as an “operator holding significant market power” in the access and call origination on public mobile telephone network market.

We hereby confirm that the above-mentioned explanations are furnished as per the provisions of the Communiqué Serial no VIII/39, that they reflect all information we have gathered so far, that they are in accordance with our corporate documents, that we have used all endeavours to collect the complete and true related information and that we assume the responsibility for this disclosure.

TURKCELL ILETISIM HIZMETLERI A.S.

Koray Ozturkler
Investor Relations
28.12.2005, 16:30

Nihat Narin
Investor Relations
28.12.2005, 16:30

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, Turkcell Iletisim Hizmetleri A.S. has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.