Mobil Oil formally announced yesterday that it has awarded a $616,000, three-year grant to Young Audiences, a national arts organization, to start a Washington chapter.

The announcement, made at a luncheon at the Charles Young Elementary School yesterday, was scheduled for last June but was postponed due to community concerns that Young Audiences would overrun the territory of local educationally oriented arts groups.

The New York-based Young Audiences, with 36 chapters around the country, books performing arts groups into D.C. schools. The group plans to begin programming in March. Local performers and a local executive director will be hired. In addition, a governing board has been established.

"We now are placing a greater emphasis on social and cultural programs which yield benefits to the disadvantaged," said Herbert Schmertz, vice president of public affairs for Mobil. "This new involvement with Young Audiences reflects the new direction we are taking."

Guests at the luncheon included D.C. School Superintendent Floretta McKenzie, actress Celeste Holm, a member of Young Audiences' National Advisory Committee, other officials from the D.C. schools and Mobil.

By yesterday, most of the initial concerns appeared to have been put to rest. But it is still vague what exactly Young Audiences will do here. "The potential that Young Audiences can offer is immense -- as long as it complements what is already being offered to the school system," says Peter Jablow, director of the Cultural Alliance. Jablow was on an ad hoc advisory committee set up by Young Audiences this summer to help the group start the local chapter. "Frankly, I don't think we ever finished our work," Jablow said, "because there are still questions left unanswered--like what programming will be done next year."

"I would agree," said Richard Bell, Young Audiences' director of national services, "I think there have got to be questions." Bell said a program design has been put together by the advisory committee, but a staff will have to implement the program and the new incorporating board will have to set policy.

None of the members of the advisory committee, which includes local arts administrators, arts activists and school officials, are on the board. The incorporating board will be presided over by James Banks of the Washington Board of Realtors and will include art collector Olga Hirshhorn; lawyer Robert Linowes (formerly president of the Greater Washington Board of Trade); David O. Maxwell, chairman of the board of Federal National Mortgage Association; Flaxie Pinkett, president of John R. Pinkett, Inc,; Jack Valenti, president of the Motion Picture Association of America; and arts patron Ann Vanderpool.

Bell said Young Audiences was looking for people with "longstanding experience . . . and stature in the community." Bell said Young Audiences took suggestions from a variety of people for board members. The board, he said, will be expanded to 20 people and eventually may include more arts administrators.