PORTLAND – Daniel E. O’Leary has resigned as director of the Portland Museum of Art and will take over as the director of the Winslow Homer Studio Project in Prouts Neck.

O’Leary’s resignation became effective Tuesday. Deputy director Thomas Denenberg has been named the museum’s acting director until a new director is hired. A search committee will be formed this summer.

O’Leary was hired as director of the Portland museum in 1993. Under his direction, the museum’s budget grew from $1.8 million to $4.6 million, with a $29.6 million increase in the endowment. Annual attendance has also increased from 90,000 to 150,000 visitors annually.

O’Leary came to the Portland institution, Maine’s largest art museum, from the Minneapolis Institute of Arts.

The Winslow Homer Studio was created in 1883 as a home and workplace for the artist, who lived and painted there until his death in 1910. The Portland Museum of Art acquired the studio on Jan. 31, 2006. The studio and surrounding grounds are currently undergoing restoration and are closed to the public.