The article about four Yasuo Kuniyoshi paintings sold by American art museums {Style, June 19} related a most unfortunate occurrence. Apparently the paintings were deaccessioned in response to a private dealer's "irresistible offers." The museums had previously not intended to remove the paintings.

What strange behavior for museums. The contents of our nation's collecting institutions won't be around for long if this is how things are cared for. Museums are preservation organizations. They exist to save art, historical artifacts and scientific specimens. This obligation is what makes museums unique -- nothing else. Selling collections on the commercial market is hardly a preservation act, especially if the buyer just walks in off the street. Items can be damaged, separated from their own histories, irreversibly altered or lost forever. Clearly if collections must be removed, transfer to another preservation organization is the preferable course.

The Kuniyoshi pictures are slated to be shown in a Japanese museum. On the surface this might seem a happy circumstance. However, most art museums in that country are privately owned and operated. The collections belong to individuals or commercial corporations, and, though open to the public, they are considered a corporate or personal asset indistinguishable from other property such as office furniture, equipment or real estate. As with similar collections in the United States, this arrangement hardly bodes well for the long-term preservation of the collections in question.

As assistant director of the Maine State Museum, I am aware that museums must be able to remove as well as add acquisitions. There are several quite legitimate reasons for deaccessioning. These include the demise of a museum, the inappropriateness of a previously made acquisition or, the inherent danger an item may pose for an institution. Yet, separating collections should be an exceptional act undertaken for noncommercial reasons. As with all decisions regarding museum collections, deaccessioning is done best when implemented for the good of the removed item. Alas, this is not always the case.

Obviously some American museums insist on getting rid of collections by selling them. Usually the offending items are hauled off to auction. While contradicting a museum's fundamental preservation task, these bizarre dealings by shortsighted organizations are beginning to have adverse repercussions for all museums in the United States. People used to assume items owned by museums would be cared for in perpetuity. Today an assault has been mounted on that essential foundation of trust. How embarrassing that it comes from inside museums.

Museums are supported by the public. People give time, money and objects because of a belief that preserving cultural materials is important. Will citizen largess continue if museums appear to be such cavalier stewards as the Terra Museum of American Art, the Baltimore Museum of Art, the Nelson-Atkins Museum of Art or the Dallas Museum of Fine Arts? Quite frankly, I suspect not.

STEVEN MILLER Augusta, Maine