Whitman's protege Curtis Jensen will be Third Avenue's sole investment chief, according to the paper's online edition.
There will not be any changes in the way the firm's portfolios are managed, the paper cited Jensen as saying in a statement.
We intend to continue our long-term practice of following the philosophy that Marty created, the paper quoted Jensen as saying.
Whitman, 85, will remain co-manager of the Third Avenue Value Fund, according to the paper.
Third Avenue could not be immediately reached for comment by Reuters outside regular U.S. business hours.
(Reporting by Ajay Kamalakaran in Bangalore; Editing by Anshuman Daga)