As a black University of Michigan business school graduate in the mid-1950s, William Bell said, he found the doors of major corporations in Detroit closed to him. He had to settle for a $75-a-week bank teller's position, the first in a succession of modest jobs he held until the founding five years ago of his own recruiting firm, Bold Concepts Inc., of which he is the president and sole employe.

The firm has never been listed with Detroit telephone information or in either the white or yellow page directories. So far this year, Bell said, Bold Concepts Inc. has not placed a single employe.

Affirmative action question: Should Bell now be elevated to control of an operation with a $140 million annual budget and 3,376 employes?

The Reagan White House thinks so and has nominated him to be chairman of the Equal Employment Opportunity Commission.

Civil rights groups disagree and have launched an attack on his nomination, arguing that he is not capable of effectively running the chief federal agency charged with enforcing federal laws against employment discrimination.

"The guy is just obviously unqualified to hold a job of this stature," said Arnoldo S. Torres, executive director of the League of United Latin American Citizens (LULAC).

"He is not qualified, not qualifiable, simple as that," said Maudine Cooper, Washington representative for the National Urban League. "You're talking about an agency with 50,000 cases, some 400 lawyers."

Sen. Orrin G. Hatch (R-Utah), chairman of the Labor and Human Resources Committee, which held Bell's confirmation hearing, defended the nomination: "He seems to be intelligent. He seems to be honorable and he is a member of a minority and should have the right amount of compassion." Hatch added that he believed it would be necessary for Bell to have a strong deputy to assist him.

Bell's nomination has embarrassed blacks in the administration and Republicans in Michigan, neither of whom reportedly were consulted before it was announced. Bell, 54, apparently was a find of the White House personnel office after several other blacks turned down offers for the job, and his name was sent to the Senate last July. A hearing on the nomination was held Oct. 6 but of the 16 members of the committee, only Hatch showed up for it. The committee has not voted on the nomination.

Democrats on the committee did submit to Bell a list of questions about his career and his views on equal employment opportunity matters. It was Bell's written response to those questions that stirred the belated opposition of civil rights groups to the nomination.

Civil rights groups had expressed reservations about Bell for some time but were reluctant to oppose him because he was one of the handful of blacks the White House has nominated. Some Democratic senators also had reservations, but refrained from voicing them publicly, according to Capitol Hill staff, because the civil rights groups were silent. Then, on Monday, civil rights groups, led by Torres' LULAC, announced they would oppose Bell. The same day, Sen. Thomas F. Eagleton (D-Mo.) informed Bell of his opposition to the nomination. Sen. Edward M. Kennedy (D-Mass.) announced his opposition yesterday.

Bell has been closely identified with the minority conservative wing in Michigan's Republican Party, and got 5 percent of the vote in a congressional race last year against incumbent Democrat John Conyers of Detroit. He also worked for a year as a consultant to the EEOC during the Ford administration, trying, he said, "to improve the image" of the agency.

Although he has claimed to have been active in civil rights organizations for years, neither national nor local groups in Detroit had heard of him. "Well, I'm just an obscure figure, I suppose," he said in an interview. "I was never really very active in the NAACP since, perhaps, in the middle '60s. My main work has been in ad hoc committees."

He also said in his application for the EEOC job that he had been a district chairman in Michigan in the Reagan campaign. Republicans in the state said that is not true.

Bell said he believes he is qualified for the post because, "I have been the chairman and on the boards of a number of organizations that have employed hundreds of people that have had access to tens of thousands of dollars."

Far less money is involved in his own business, which he says he has been phasing down this year because of the EEOC nomination.

In the interview and in response to the Democrats' questions, Bell said he founded Bold Concepts Inc. five years ago but did not get a license for it until two years later because "I did not start recruiting until 1978." He and his wife, a secretary at a Detroit department store, are the only stockholders of the firm, for which he listed an annual income of $7,000.

The firm is housed in the office of his younger brother, Edward, a well-known criminal lawyer in Detroit. Does he pay rent? "Not as such," he said.

Bell said he has worked as an insurance agent, real estate salesman, magazine distributor and investment consultant. Asked what he is most proud of accomplishing during his career, he said, "Well, I'm proud to have survived. It's been a hostile and unfriendly environment for a person who had my background . . . . After the equal employment opportunity thrust had come into being I was no longer in my 20s."