In a major shift of power, 41-year-old Washington attorney Harry Teter was named president of the New National Theatre Corp. (NNTC) yesterday by unanimous vote of the board of trustees and given all executive powers previously held by Maurice B. Tobin.

At the same time, Tobin was appointed to the newly created post of chairman. Although during his eight-year tenure as unpaid head of the theater, Tobin had sometimes used the title of chairman, the position did not exist. In his new role, Tobin will oversee the National's fund-raising efforts and public service programs, including Noon at the National and the children's theater.

The change is generally viewed as part of a much-needed housecleaning at the National and a first step toward mending relations with the Shubert Organization in New York, which books the National and with which Tobin had been openly feuding for nearly two years.

Teter said yesterday that he would be meeting with the Shuberts "as soon as possible" and added that "I expect to invite them to all board meetings in the future." In the past, Tobin actively had sought to bar any direct communication between the Shuberts and the NNTC board.

"If this sticks and it's real, the situation should get much better," Bernard Jacobs, president of the Shubert Organization, said yesterday. "Harry is a responsible person, aware of theater problems and what makes for a compatible working relationship. I think he's an excellent choice."

Yesterday's resolution, also aimed at putting the precarious financial situation of the National in order, called for the creation of an annual budget and a management committee, to be chaired by the president and entrusted with the general management of the theater.

"All expenses are now at a freeze level," said Teter. "There are no contracts except those that we need to keep going day by day. Everything will be reviewed." Immediately affected was Jerry Campbell, whom Tobin had hired eight months ago as director of development and whose resignation was announced yesterday at the meeting.

Teter said that the Shuberts' next payment to NNTC, under their profit-sharing arrangement, would put NNTC in the black. "But we will have to watch our expenses very carefully," he said.

Tobin closed the National on May 2--presumably for renovations, although work has only just now begun--and promised to reopen the theater by Sept. 15. "We certainly hope to open by then," Teter said. "But we shouldn't hold out any false hopes. I would like to meet first with the developers and get a clear commitment from them on a time schedule before making any announcement."

Teter, who has produced plays at an Equity summer theater in Virginia, has been a member of the NNTC board for four years. Before the Shubert Organization was engaged to book the National two years ago, Teter handled that job for NNTC.