Dec 12 (Reuters) - Perpetual Ltd's top investor, Australian diversified investment firm Washington H. Soul Pattinson and Company (WHSP), has increased its stake in the company to 11.66%, according to an exchange filing on Tuesday.

The stake increase comes after the fund manager rejected WHSP's A$3.1 billion ($2.04 billion) takeover offer last week. ($1 = 1.5165 Australian dollars) (Reporting by Nausheen Thusoo in Bengaluru; Editing by Rashmi Aich)