With Mayor Washington and six members of the D.C. City Council in the audience, Lisle C. Carter Jr. yesterday officially accepted appointment as the first president of the University of the District of Columbia, and then made a strong appeal to keep politics out of the university's affairs.

Carter, a 51-year-old lawyer who currently heads the Atlanta University Center, declared that Washington's new public university should be "outside of and beyond politics."

Although Carter himslef has taken part in several presidential campaigns, most prominently in George McGovern's losing effort in 1972. Carter said yesterday that decisions affecting the university must be made on educational grounds alone.

"Some may tend to see the development of U.D.C. as one more piece of theater on the glamorous stage that is one aspect of Washington." Carter remarked. "Others may see it as a minor piece on the large chess board of politics. But it is not and cannot be either of these things."

The university, which offically began operating yesterday, is being created by a merger of the city's three low-tuition public colleges - Federal City College, Washington Technical Institute, and D.C. Teachers College.

Last year they had a combined environment of 8.939 full-time equivalent students with a head-count of about 13,000, including part-timers. The university has requested $41.3 million next years from the District government and expects $8.6 million in federal gransts.

Yesterday, Carter said, he will be getting a $52,000 salary in his new post plus a $12,000 annual housing allowance.

The salary is the second highest in the District government, just $500 below Mayor Washington's but the major receives no allowance for housing.

However, officials of several national education organizations said yesterday that Carter's salary is comparable to that of presidents at other large public universities.

At the University of Maryland, for example, president Wilson Elkins was paid $50,400 last year, received free house with a paid housekeeper and a $21,000 "operating allowance."

Wendell P. Russell, who served as president of both FCC and DCTC, and Cleveland Dennard, the former president of WTI, each received $43,950 this year plus a housing allwance of $7,200 apiece.

Carter made his statement yesterday at the National Press Club and briefly answered questions from reporters.However, most of the approximately 150 persons in the club's flagbedecked ballroom were university officials and city politicians. They gave Carter two standing ovations.

When he finished, Mayor Washington rushed up and shook Carter's hand. Many others in the room passed by Carter in a receiving line.

Ronald H. Brown, the chairman of the university trustees who selected Carter Thursday night, said he was "very pleased, proud, and excited" about the board's choice, and described Carter as a man of "brilliance, commitment and dedication."

In mid-June, the trustees' first choice for the job, Randolph W. Bromery, chancellor of the University of Massachusetts at Amherst, turned down the board's offer.

Brown said the new president will take office on September 30, but will begin work part-time soon as a member of an interim executive committee that will also include Russell and Claude Ford, the acting president of WTI.

Although Brown declared that the top administrative and financial structure of the three coleges had been consolidated, their academic programs will continue to be separate this fall.

In his statement, Carter cautioned that consolidating programs will "take time" because planning in a university is a "widely consultative process."

Although differences between vocational programs at WTI and the liberal arts emphasis at Federal City have caused conflicts in the past. Carter urged that those differences between the two not be "overstressed."

Carter himself graduated from Dartmouth College at age 18, and went to St. John's University Law School in Brooklyn.

During the 1960s, he worked for both the Kennedy and Johnson administrations and was an assistant secretary of Health, Education, and Welfare from 1966 to 1968. Afterwards, he was a professor of public policy and vice president at Cornell University before going to the Atlanta University Center, a consortium of six predomiantly black colleges, in 1974.