In Eric Cruz's Puerto Rican neighborhood in the Bronx, nobody talks much about business. Until he attended the corporate-sponsored "LEAD Program in Business" last month, Eric, who will be a senior this fall at Birch Wathen High School, always thought he wanted to be a doctor.

After a recent visit to the Chicago Mercantile Exchange sponsored by the LEAD program, Marvin Woods said the trading floor looked "as unorganized as a bunch of ants." Marvin, who will graduate next May from Detroit's Renaissance High School, believes many blacks "make it to the top and then forget their heritage." Marvin promises he won't forget.

Poonam Khana joined Cruz, Woods and 116 other minority high school students last month on four college campuses to learn about the world of business. Khana, an American Indian, said most qualified minority students go into law or medicine because they lack role models in business. "The stereotypical image of the businessman among minority youth is as a cheater," she said.

The disturbing lack of minority representation in business schools and in corporate offices across the nation led to the formation of LEAD (Leadership, Education and Development), a program set up with funds donated by major corporations. Its purpose is to offer minority high school students exposure to the world of business at a time when many are making college and career choices.

All expenses for the program are paid by sponsoring corporations, which this year donated between $225,000 and $250,000. McNeil Consumer Products, General Motors, Jewel Co. and PepsiCo each contributed $25,000 this year as LEAD's principal sponsors. The pilot program, held in 1980 at the Wharton School, had the support of 25 corporations.

Richard J. Scarperi, president of LEAD, said the program will be on 10 campuses by 1985, including a program next summer in Washington sponsored by the University of Maryland in cooperation with Howard University. he University of Virginia will host a LEAD program next summer. The University of Texas, Stanford and Harvard are reported close to a decision to sponsor programs on their campuses next year, and UCLA is said to be considering the idea.

Last month, students gathered at four universities -- Northwestern, Pennsylvania (the Wharton School), Michigan and Columbia -- to hear presentations by faculty of the respective business schools and to listen to corporate executives who tried to persuade the teen-agers that businesses need and want minority group members to work in their midst.

"These are bright kids who are carefully picked for the LEAD program because they want to give back to their communities," said Scarperi. "Most of them are considering law or medicine, which have always been thought of as noble professions.

"We want to encourage them to think about business as an alternative, and even if they don't all go to business school, the chance to spend a month together in a constructive climate is going to have a positive influence on their lives," he said.

In addition to field trips to corporate offices and plants, the students spend considerable time in classes that are strikingly similar to those offered by graduate business schools. Much of the instruction is through the casebook method where students are presented with a dilemma and then asked to make a business decision.

To add an element of the real world to the classes, many of the cases are reviewed by guest executives from participating companies.

"We want to keep geographical diversity at each program so even when there are 10 programs, the kids will have travel provided to campuses in other parts of the country," Scarperi said. "What's frightening is that the trends indicate the shortage of minorities in business schools is going to get worse. The LEAD program is really a long-term investment in a long-term problem."

From 1973 to 1980, the percentage of women attending undergraduate business schools increased from 19 percent to 40 percent, according to the Educational Testing Service. The number of minority students increased less than one percent, from 10.8 to 11.2 percent. t the graduate level, admissions counselors at the nation's leading business schools complain that they are all fighting for a limited number of select minority students. They also fear that cuts in financial aid will make it difficult, if not impossible, for many students to attend.

At Stanford University, officials estimate graduate business school students will spend an average $15,000 for tuition, books and living expenses in the coming year. There are 46 minority students (14 percent) in the class that entered last fall, somewhat less than the 54 foreign students in the class of '83.

At both Wharton and Harvard, the problems is more severe. At Harvard, the class of '81's 767 students included 146 foreign students and 55 minority students. At Wharton, 19.7 percent of the class of '82 were foreign students and 7.4 percent were minorities.

"A lot of the problem we are strapped with is lack of financial aid money," said Janis King, assistant director of admissions at Wharton. "We also have to show minority group members that there is room for professional advancement in business . . . or they'll continue to concentrate in law and medicine," she said.

One university that has plenty of minority business students is Florida A&M's School of Business and Industry, where 96 percent of the school's 1,000 undergraduates are black. Corporations recruited so heavily at the business school in Tallahassee last year that university officials advised students to stop interviewing.

"Most of our students had 12 to 15 offers last year, and they're the most aggressively recruited undergrads in the nation," boasts Dean Sybil Mobley, who has held that post since the school was founded in 1974. "Most of the students who end up in business school here were thinking about law, medicine or engineering before we recruited them," she said.

Mobley, who has received promises from 20 corporations that have agreed to contribute $100,000 each to the school's endowment fund, fears the immediate future for blacks in corporate America is bleak. "Just as the opportunities are opening up, the educational funds are drying up," she lamented.

The scarcity of minority students in business schools is so great, she said, that many corporations recruit students at the high school level and recommend that they attend Florida A&M. The school has one thing most other business schools don't have; a professional development program. his professional development program prepares students for the "real world" of business by superimposing the business culture on the academic world, Mobley explained. One of the great failings of many leading business schools, according to corporations that recruit in Tallahasse, is that they don't prepare their students for corporate life, she said.

Many blacks don't feel they belong in corporate America, acccording to Glegg Watson, co-author of "Black Life in Corporate America," a book set for publication on August 20. The book, based on more than 160 interviews, explains the "psychological prices many minorities pay for the rewards of prestige, money, and power."