Form 10-K SECURITIES AND EXCHANGE COMMISSION For the fiscal year ended December 31, 2018 W. R. BERKLEY CORPORATION Title of Each Class Name of Each Exchange on Which Registered Common Stock, par value $.20 per share New York Stock Exchange 5.625% Subordinated Debentures due 2053 New York Stock Exchange 5.9% Subordinated Debentures due 2056 New York Stock Exchange 5.75% Subordinated Debentures due 2056 New York Stock Exchange 5.70% Subordinated Debentures due 2058 New York Stock Exchange Washington, D.C. 20549 (Mark One) [x] ANNUAL REPORT PURSUANT TO SECTION 13 or 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 OR [ ] TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from ______ to ______. Commission file number 1-15202 Delaware (Exact name of registrant as specified in its charter) (State or other jurisdiction of incorporation or organization) 475 Steamboat Road, Greenwich, CT (Address of principal executive offices) Registrant’s telephone number, including area code: (203) 629-3000 Securities registered pursuant to Section 12(b) of the Act: 22-1867895 (I.R.S. Employer Identification Number) 06830 (Zip Code) Securities registered pursuant to Section 12(g) of the Act: None Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.   Yes S No o Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or 15(d) of the Act.   Yes o No S 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 S No o 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 S No o Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K. S