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Table of Contents FORM 10 - K ( Mark one ) ANNUAL REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31 , 2020 OR □ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from No UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington , D.C. 20549 Commission file number 001-38373 Switzerland ( State or other jurisdiction of incorporation or organization ) Turmstrasse 30 Steinhausen , Switzerland ( Address of principal executive offices ) Indicate by check mark whether TRANSOCEAN LTD . ( Exact name of registrant as specified in its charter ) Title of each class Transocean to Shares , CHF 0.10 per share 0.50 % Exchangeable Senior Bonds due 2023 Registrant's telephone number , including area code : +41 ( 41 ) 749-0500 Securities registered pursuant to Section 12 ( b ) of the Act : Trading symbol RIG RIG / 23 registrant is a well - kn ( I.R.S. Employer Identification No. ) 98-0599916 Securities registered pursuant to Section 12 ( g ) of the Act : None 6312 ( Zip Code ) Name of each exchange on which registered New York Stock Exchange New York Stock Exchange seasoned issuer , as defined in Rule 405 of the Securities Act . Yes ✔ Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15 ( d ) of the Exchange Act . Yes No ✔ Indicate by check mark whether the registrant ( 1 ) has filed all reports required to be filed by Section 13 or 15 ( d ) of the Securities Exchange Act of 1934 during the preceding 12 months ( or for such shorter period that the registrant was required to file such reports ) , and ( 2 ) has been subject to such filing requirements for the past 90 days . Yes No Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S - T during the preceding 12 months ( or for such shorter period that the registrant was required to submit such files ) . Yes No Large accelerated filer Accelerated filer Non - accelerated filer Smaller reporting company Emerging growth company Indicate by check mark whether the registrant is a large accelerated filer , an accelerated filer , a non - accelerated filer , smaller reporting company or an emerging growth company . See the definitions of " large accelerated filer , " " accelerated filer " , " smaller reporting company " and " emerging growth company " in Rule 12b - 2 of the Exchange Act . If an emerging growth company , indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13 ( a ) of the Exchange Act . Indicate by check mark whether the registrant has filed a report on and attestation to its management's assessment of the effectiveness of its internal control over financial reporting under Section 404 ( b ) of the Sarbanes - Oxley Act ( 15 U.S.C. 7262 ( b ) ) by the registered public accounting firm that prepared or issued its audit report . Indicate by check mark whether the registrant is a shell company ( as defined by Rule 12b - 2 of the Exchange Act ) . Yes No As of June 30 , 2020 , 614,612,545 shares were outstanding and the aggregate market value of shares held by non - affiliates was approximately $ 1.12 billion ( based on the reported closing market price of the shares of Transocean Ltd. on June 30 , 2020 of $ 1.83 per share and assuming that all directors and executive officers of the Company are “ affiliates , " although the Company does not acknowledge that any such person is actually an " affiliate " within the meaning of the federal securities laws ) . As of February 16 , 2021 , 616,025,144 shares were outstanding . DOCUMENTS INCORPORATED BY REFERENCE Portions of the registrant's definitive Proxy Statement to be filed with the United States Securities and Exchange Commission within 120 days of December 31 , 2020 , for its 2021 annual general meeting of shareholders , are incorporated by reference into Part III of this Form 10 - K .