The Phillips Collection has consigned one of its early Georges Braque paintings to auction later this fall, officials at the museum said yesterday. The proceeds from the sale of the French painter's "Music," not part of founder Duncan Phillips' original permanent collection, will go toward an endowment "to provide a guaranteed base of operations for the museum."

The 1914 painting, donated in 1953 by Katherine S. Dreier, is expected to sell for between $3 million and $4 million at Sotheby's in New York Nov. 11. The auction house will sell "Music" together with Vincent van Gogh's "Irises" after a week-long public viewing there. Before that the paintings will travel to Osaka, Tokyo and London. The price of "Irises" is expected to exceed $20 million, in the wake of spectacular upward price trends in the art market. Because of that, the price of "Music" might go higher than expected.

"Wedon't like to sell off paintings, but we felt this particular work fit in less well with the others now owned by the gallery," said Laughlin Phillips, director of the museum. He pointed out that "Music," in oil, sawdust and black crayon, is "one of the best examples of analytical cubism from Braque -- it's cool, austere, cerebral." In contrast, he said, the museum's 13 later Braque pieces are warmer and belong together. "This is a brilliant painting, but it did not have the close identification with what Duncan Phillips wanted to do as the others," said Phillips.

ThePhillips has periodically sold off paintings over the past few years, including a Max Ernst painting from the same Dreier bequest. The funds from the sale will go only to the endowment fund, part of a three-pronged financial effort that also attempts to raise public donations specifically for renovation and expansion. The effort has been successful so far, said Phillips. He said the collection is operating at a surplus now, though he declined to be more specific. The museum is also in the midst of a $9.5 million refurbishment program, to be completed in 1989.

"The monies from this sale will go to taking care of what we've got," said Phillips. "We're not doing what we'd like in terms of conservation, research and publications about the permanent collection -- this sale will help us get there."

But the sale brings up questions about the Phillips' "deaccession" plans. Currently, the museum has no resources to buy more works, especially at today's inflated prices. New curatorial department chairman Lawrence Gowing is expected to reexamine the permanent collection, and his department has suggested to Phillips that sales of some works might be a way to raise funds for new works. That possibility, he said, would be "up for discussion" at the next board of trustees meeting on Monday.