Tracinda says Tesoro rights plan threatens tender

NEW YORK, Nov 26 (Reuters) - Investor Kirk Kerkorian's Tracinda Corp on Monday said that refiner Tesoro Corp's (TSO.N) decision to adopt a "poison pill" shareholder rights plan could jeopardize its offer to buy 16 percent of Tesoro's shares.

Tracinda launched an attempt last month to buy up to 21.9 million shares at $64 a share, a nearly 12 percent premium over where the shares were then trading. If completed, the tender offer would bring Tracinda's total stake in the company to 19.98 percent.

Tesoro adopted the rights plan last week. The plan would make it more costly and complicated for Kerkorian to launch a hostile bid for the refiner.

Tracinda said it believes the rights plan significantly limits opportunities to enhance stockholder value and has a material adverse effect on the value of Tesoro's common shares. (Reporting by Michael Erman, editing by Gerald E. McCormick)