Five faculty members yesterday wrote to President Neil L. Rudenstine expressing "outrage" at the University's decision to invite Colin L. Powell, chair of the Joint Chiefs of Staff, to speak at Commencement and to receive an honorary degree.

The letter, some faculty members said yesterday, might be only the beginning in a series of faculty reactions to the controversial invitation.

"I have certainly heard a number of faculty saying it was a highly inappropriate invitation, if not worse," said Professor of Philosophy Warren D. Goldfarb, who spoke out against Powell's invitation last week.

"I certainly expect other letters," added Goldfarb, who is gay. "I know of at least a couple of other faculty members preparing letters."

Faculty members are slated to speak at a rally tomorrow to protest the invitation, and some of the letter's signatories said they see broad-based support for their stance among both gay and straight colleagues.

The five professors called for "an immediate apology for Powell's invi- tation, in the form of a public reaffirmation of the University's commitment...to the full and equal rights of--specifically--its gay and lesbian faculty, staff and students." They also demanded that Rudenstine "speak out at Commencement to dissociate our University from General Powell's bigotry."

"We feel it's important for the faculty to speak out about it," said Jeffrey A. Masten, assistant professor of English and American literature and language.

Masten plans to attend tomorrow's rally, he said, and "a number of faculty members will be there" as well.

The letter's signatories said yesterday they were shocked and dismayed when they found out about the invitation.

"I felt a combination of confusion and outrage," said Assistant Professor of English and American Literature and Afro-American Studies Phillip B. Harper. "Outrage outweighed the confusion."

And many agreed the five who signed the letter are far from the only faculty members with criticisms of the choice of Powell.

Professor of English and Comparative Literature Barbara E. Johnson, who signed the letter to Rudenstine, said the decision to refer to the letter's signatories as "gay and lesbian members of the faculty" excluded the straight supporters of its stance from signing.

The writers felt "it was important to say there was a constituency" of gay and lesbian professors concerned about the issue, she said.

Harper said "the signatories are just a few people who decided to support this particular letter," while many others opposed the Powell invitation.

Thurston A. Smith, associate registrar of the Faculty, who was not one of the letter's signatories, said he has heard both gay and straight faculty criticism of the invitation