LOS ANGELES (AP) _ Aging political radicals say they may come out of retirement to fight their planned ouster from Sunset Hall, a home set aside especially for elderly social reformers.

''It's the loss of a very important people's institution,'' said Sadie Tomkin, 89, a longtime communist and a former manager of ''People's World,'' a communist publication.

''If this was a decent society, this would never have happened,'' she added.

Sunset Hall, a 36-room Spanish-style building, will be sold for $1.2 million to a developer who wants to convert it into an apartment house, said Ann Maupin, president of the board governing the home.

Residents have until March 22 to move out, she said, adding that the 18 Sunset Hall inhabitants, ranging in age from 77 to 99, fell victim to a longtime foe - the bottom line.

''We're not happy about this, but we feel that, economically, we are simply not able to go on,'' Ms. Maupin said.

Sunset Hall, founded in 1924 by the First Unitarian Church of Los Angeles, was designed to house so-called elderly ''religious liberals.'' The home is funded primarily by residents' monthly fees and has operated at a deficit for nearly 20 years, said administrator Thomas E. Brandlin.

It is expected to suffer an estimated $95,000 deficit this year, its worst ever, he said.

Many living there helped unionize the United States in the 1930s and fought McCarthy-era blacklisting in the 1950s.

Residents have included Waldemar Hille, who collaborated with folk singer Pete Seeger, and Ruben Burroughs, newsletter editor for Upton Sinclair during the socialist's 1934 gubernatorial campaign.

They pay between $900 and $1,400 a month, although some are charged less because of need.

Residents of the stately mansion, which features a large, tree-shaded patio, a library and a living room equipped with a grand piano, say the planned closure would be a hardship.

''I'm broken-hearted,'' said Sylvia Cochran, who will turn 100 on March 23.

''We're being pushed out,'' said Faye Hyman, 89. ''Where am I going to go?''

To fight the closure, attorney Kent Brink said he intends to seek a court injunction blocking the planned sale.

Residents said if that doesn't work they'll fall back on a timeworn strategy: They'll stage a demonstration outside Sunset Hall the day they get the boot.