Decrying the "dismal" record of big business and graduate schools in attracting minorities to corporate careers, 36 major corporations announced a summer program at three universities to help acquaint minority students with business.

The July sessions, an expanded version of a program held last summer at the University of Pennsylvania's Wharton School of Business, will train a total of 90 high school students at Wharton, the University of Michigan and Northwestern University.

Under the program, which is dubbed "LEAD," high school juniors and seniors attend a four-week school at no cost, with the 36 sponsors picking up the tab. This July's sessions include 71 blacks, 12 hispanics, six Asian-Americans and one Native American among the 47 women and 43 men.

Peter Scarperi, president of LEAD, cited research showing that top minority students tend to study law or medicine rather than head for a business career. Graduate enrollments show 9,016 minority students in graduate business schools in 1980, about 20 percent of the total enrolled, versus 7,117 in 1978.

"The numbers show that our major corporations are not getting enough minorities in the pipeline for careers in operating management," said Scarperi. He said the LEAD program is aimed at high school students because minority students' career preferences tend to form before college.

The inclusion of Northwestern and the University of Michigan was announced formally at a dinner last night attended by representatives of most participating corporations. The keynote speaker was Murray L. Weidenbaum, chairman of the president's Council of Economic Advisors.