President Reagan returned to work on domestic political problems after his speech at the United Nations today, speaking to a group of women athletes here and then returning to Washington to address a group of black college officials at the White House.

Donna de Varona, chairman of the Women's Sports Foundation and a former Olympic Games swimming champion, told the president before he spoke today that American women would like to see "the language in Title IX stay intact."

Title IX of the U.S. Education Act prohibits sex discrimination at institutions receiving federal funding. The Justice Department recently announced support of a lawsuit that would limit the effect of the law to proven cases of sex discrimination, thereby lessening the extent of federal review for possible cases of discrimination.

Reagan told the athletes that his administration has a strong interest in protecting women's rights. He said that his policies in support of women are one of the "best kept secrets in Washington" and that he is trying to "get the truth out."

Apparently responding to the group's recommendations that he leave Title IX unchanged, Reagan said, "Let me pause and say, I can understand your suggestion to me, but I also want to say to you in my own behalf that there have been some misconceptions about what my attitude might be . . . . "

The president later attended a White House reception for historically black colleges and universities.

The occasion was the signing of a bill to amend Title III of the Challenge Grant Program to offer increased financial help to black schools. With Vice President Bush and Mrs. Bush and Education Secretary T.H. Bell in attendance, Reagan recalled that his administration last year identified 27 federal agencies offering grants to colleges and universities for research.

He said these agencies "will be providing 11 1/2 percent more federal funding to your universities and colleges in 1983 than they did in 1982."

Reagan said he backed changes in the law to ensure that smaller schools receive more federal funds because, he said, "there is no reason" for federal research in colleges and universities to be done only by large institutions.

"But federal research grants and other government subsidies are not an end in themselves," Reagan told the group.

"We must continue to work toward the goal of self-sufficiency . . . ."