NEW YORK, JULY 24 -- The National Endowment for the Arts has asked an outpost of avant-garde art to provide a detailed description of its upcoming season within 30 days or face a loss of funding, both parties said today.

The endowment called it a routine request. But the Franklin Furnace Archives, a Manhattan museum that presents experimental performance and visual art, described it as "harassment" aimed at performances some consider obscene.

"The NEA is making this request because the Furnace's whole purpose on this earth is to show avant-garde art," said Barbara Pollack, the museum's spokeswoman. Such art "doesn't fit in with {Sen. Jesse} Helms's definition of what should receive funding," she added.

The four performance artists whom the NEA turned down for grants in June have performed at Franklin Furnace or received funding from it, Pollack said. And an installation by Karen Finley, one of the four, is currently on display at the organization's gallery.

In one of her performance pieces, Finley dances nude and smears her body with chocolate to show the degradation of women.

Martha Wilson, founder and director of Franklin Furnace, was traveling and unavailable for comment on the endowment's request.

The request came after Franklin Furnace was notified in early June that the NEA had approved a $20,000 grant for its visual and performing arts programs and a $7,500 grant for audience development.

The museum accepted the grant, signing the anti-obscenity pledge the NEA requires of grantees. Congress last year put strings on government aid to the arts by adding language to a 1990 spending bill that forbids the endowment from funding works that might be deemed obscene.

In a letter dated July 13 but received Monday, the NEA asked Franklin Furnace for "identification of the artists involved and the nature of the work to be performed or installed" in order to make a "final determination" on its grant application.

Failure to respond to the request within 30 days "will result in the rejection of this application," Julianne R. Davis, the endowment's general counsel, wrote to Franklin Furnace.

In a statement today, Davis said, "A number of endowment programs have, for many years, routinely required the submission of additional information at appropriate times."

Many arts organizations have not fully booked their upcoming season when they apply for grants, and it is not unusual for the NEA to later request a description of what is planned, said Kathy Christie, an endowment spokeswoman.

Pollack is suspicious, however. She cited a June 21 call from the General Accounting Office asking for information on four performance artists, including Finley. She said the GAO had been asked in March by Helms, the Republican senator from North Carolina, to look into "possible violations of law by the NEA."

Now, she said, "what they want to do is get a broader list of who to investigate. We do not want to assist them in developing a blacklist."