Mary Berry, Assistant Secretary of Health, Education and Welfare, told a conference of black college presidents yesterday that President Carter is "personally committed" to seeing that their institutions grow stronger by the end of his administration.

In a keynote address, Berry detailed efforts by the Carter administration to improve the lot of higher education for blacks during his first 22 months in the White House.

Among the administration's accomplishments, Berry told the group of more than 150 administrators gathered at the Capital Hilton, was the successful desegregation of a number of historically all-white colleges and universities.

"We do not believe that the future of black colleges is threatened by desegregation," Berry said in an interview before her speech. "We believe that black institutions must be strengthened, not weakened in the desegregation process."

The three-day conference, which ends today, is sponsored by the National Association for Equal Opportunity in Higher Education and HEW.

Berry said that although new guidelines affecting money allocations under Title III of the Higher Education Act, a major source of funding for most black schools, have been changed, black institutions will not suffer significant losses of funds.

"The bulk of Title III funds will still be committed to developing institutions, which means a major share of the funds will go to the black colleges," Berry said.

In an earlier luncheon speech, Frederick Humphries, president of Tennessee State University, said that black college presidents "are no longer powerless" in their ability to acquire resources to operate their institutions.

"We have come to this meeting to find out more about federal government programs," said Humphries. "But we're not begging. We are entitled to participate in those federal funding programs."

The conference, which grew out of a meeting last August among President Carter and black college presidents has consisted largely of a series of workshops that provide information about various sources of federal funding currently not fully utilized by most black institutions.