March 28 (Reuters) - SilverBow Resources said on Thursday it has rejected largest shareholder Kimmeridge Energy Management's latest offer that valued the oil and gas producer at $2.1 billion, including debt, in the latest rebuff of the asset manager's efforts. (Reporting by Vallari Srivastava and Sourasis in Bengaluru; Editing by Sriraj Kalluvila and Shilpi Majumdar)