The trustees of George Washington University are expected to name Stephen Joel Trachtenberg, the president of the University of Hartford in Connecticut, as GW's new president at a meeting today, sources at GW said yesterday.

Trachtenberg, 50, has been an advocate of private colleges, and critical of state colleges for providing what he calls "public subsidies for rich students" through low tuitions. He also has assailed Secretary of Education William J. Bennett for suggesting that American colleges are often too costly and ineffective.

At GW he would succeed Lloyd H. Elliott, a low-key administrator who has headed the university for 23 years. Elliott is scheduled to retire in June, a month after his 70th birthday.

The sources said Trachtenberg was the first choice of a 13-member presidential search committee. He visited the campus last week, speaking to groups of faculty members, students and trustees.

Yesterday George Washington's public relations office scheduled a news conference this afternoon "to announce the president-designate." In a telephone interview yesterday, Trachtenberg said he would "probably" be in Washington today but declined further comment.

He has headed the University of Hartford for 11 years, increasing its endowment sixfold.

Hartford now has about 7,500 students, compared with about 18,000 at George Washington, and about 300 full-time faculty members, compared with about 1,200 at GW.

Trachtenberg also has been a visible figure in national education debates, publishing essays in the Chronicle of Higher Education and The New York Times and speaking at education conferences here and elsewhere around the country. In an article last summer in The College Board Review, Trachtenberg accused Bennett of "scapegoating" American colleges with "hate-filled language" that paints a "picture . . . of American higher education {that} is essentially mythical."

A graduate of Yale Law School, Trachtenberg has served as a vice president of Boston University and earlier as an aide to Rep. John H. Brademas, now the president of New York University, and to Harold Howe II, when Howe was commissioner of education in the Lyndon Johnson administration. He has been active in Democratic politics and is a member of the Cosmos Club of Washington.