As part of an effort to increase its scholarly potential, the Phillips Collection has hired Eliza Rathbone, who for the past eight years has been assistant curator of 20th-century art at the National Gallery of Art.

Rathbone, 36, who once worked as a guard at the Phillips, will become associate curator there March 25. She will be third in rank under director Laughlin Phillips and curator Willem de Looper.

The Phillips, a family-run institution, has always resisted hiring museum professionals, tending to employ artists instead. This is the first time a senior art historian has been appointed to a permanent senior staff position since the departure of director Richard Friedman in 1975. Friedman resigned after it was discovered he had stolen 21 prints and drawings. The gallery did not press charges after Friedman returned seven of the works and cooperated in efforts to find the rest.

Since then, Laughlin Phillips has placed only trusted family members and close associates in staff positions. Artist Willem de Looper had worked at the Phillips since 1959, starting as a guard, before advancing to the position of curator in 1982 following the death of artist, family friend and curator James McLaughlin.

A specialist in European and American modern art, Rathbone was trained in art history at Smith College and New York University, and received her master's degree from the Courtauld Institute of the University of London.

Her name is well known in the art world. Her father, Perry Rathbone -- director of the Boston Museum of Fine Arts from 1955 to 1972, and before that of the St. Louis Art Museum -- is senior vice president and director of museum liaison at Christie's auction house in New York. Her older brother Peter is head of the American paintings department at Sotheby's in New York.

"Eliza's father was very close to my parents when he was at the Boston Museum," said Phillips. "And she has long loved the Phillipses, so it's a very happy arrangement.

"We've had several young curators who are very strong on art history -- Robin Cafritz and Sasha Newman -- but they're pursuing their PhDs, so we needed an associate curator here who could work with Willem de Looper and lecture occasionally," said Phillips.

Newman was appointed assistant curator in 1979, after serving as an intern and researcher. Robert (Robin) Cafritz, son of Jennifer Cafritz Phillips (whom Laughlin married in 1975), was appointed an assistant curator in 1978. Both are writing doctoral dissertations, she in Paris, he in New York.

At the National Gallery, Rathbone worked on several major exhibitions under curator E.A. Carmean and his successor Jack Cowart, and two recent ones on her own: "Modigliani: An Anniversary Exhibition" and "Mark Tobey: City Paintings," for which she also wrote a major catalogue.

Rathbone said she'll be paid a good deal more than when she worked at the Phillips as a guard. "But then I just had to sit and read books and look at the pictures. I expect this will be quite different."