Responding to criticism that the National Endowment for the Arts has been insensitive to minorities, chairman Livingston I. Biddle Jr. yesterday announced the appointment of a special representative for minority concerns. Biddle named Gordon Braithwaite, 39, currently the endowment's special projects director, to the post.

Out of the $123 million given by the endowment to arts groups this year, said Braithwaite, less than 2 percent went to minorities. In the last few months, an arts task force of several black and Hispanic groups has asked for increased participation in the procedures and funds of the endowment.

At their morning press conference, Biddle and Braithwaite said that the functions of the new position are still evolving. But the office will identify projects, act as a laison between minority groups and the endowment and help to increase technical assistance.

"We are going to deal with recognition and then future growth" of minority program, said Biddle. The majority of the programs now funded fall into the expansion arts category. "Expansion arts are sometimes perceived as second-class citizenship at the endowment. We want to ensure the initial access and then help programs qualify for the general programs."

A native of Atlantic City, N.J., Braithwaite worked in municipal and private cultural operations in New York City for five years. Since 1973 he has had three posts at the endowment. Final arrangements for his staff and salary are still under consideration.

"We want to look at what we encouraged in the 1960s, what we allowed in the '60s, and see what has happened," said Braithwaite. "The '70s have had it but we haven't had it. In the '80s we are moving toward a recognition of cultural diversity."

One of the endowment's strongest critics, Rep. Shirley Chisholm (N.N.Y.), reacted cautiously to Braithwaite's appointment. "While I know Gordon, and he is a fine man, there needs to be access to Mr. Biddle and mr. Duffy (Joseph Duffey, the chairman of the Endowment for the Illumanities) and changes in the affirmative-action approaches in hiring and grants-making procedures," said Chisholm.