Macerich rejects Simon Property's offer, adopts poison pill

March 17 (Reuters) - Macerich Co, the third-largest U.S. shopping mall owner, rejected a $14.39 billion offer from larger rival Simon Property Group Inc, saying the offer "substantially undervalues" the company.

Macerich also said on Tuesday that it adopted a shareholder rights plan and set the trigger at 10 percent.

(Reporting by Sagarika Jaisinghani in Bengaluru; Editing by Kirti Pandey)