Of about a dozen contenders for the chairmanship of the Securities and Exchange Commission, the apparent front-runner is Robert M. Loeffler, a respected 53-year-old attorney from Minneapolis.

Among those who are high on Loeffler is the current chairman, Roderick M. Hills, whose opinions have gained respect on Capitol Hill in the yearplus that he has held the job.

Loeffler was in town last week joining a raucous group of Minnesotans here to celebrate the inauguration of his friend, Vice President Mondale. During an interview, Loeffler said he was aware that he was under consideration, but he claimed he learned nothing about his chances during his 10-day visit to Washington.

For the investment community, the SEC chairmanship is perhaps the most important of the pending presidential appointments.

Though each of the five commissioners has one vote on all official actions, the chairman enjoys administrative clout that allows him to direct the energies of the commission. The SEC oversees the operations of the nation's stock exchanges and its publicly-owned corporations.

Loeffler, an intense, chain-smoking man, happens to be unemployed at the moment, having worked himself out of a job on the West Coast.

On April 10, 1973, Loeffler was appointed trustee in bankruptcy of Equity Funding Corp. of America, the insurance-mutual fund complex that collapsed in scandal just five days earlier.

The average Chapter 10 bankruptcy restructing takes seven years to complete.

Loeffler managed to complete the reorganization of Equity Funding by March, 1976. What made this all the more impressive was that Equity Funding was anything but an average financial collapse.

Generally viewed as one of the biggest financial frauds in U.S. history, top executives at Equity Funding were eventually charged with everything from counterfeiting stock to creating fictitious policyholders. Occasionally, these phony policyholders would be killed off, on paper, to make the fraud look authentic.

In 1972, Equity Funding showed a net worth of $143.4 million, but Loeffler's accountants learned that the company's worth was actually only $43 million.

"They didn't know what the real figures were," recalls Loeffler, "the fraud had been going on so long."

Initial reports indicated that the fraud took place for only a short time before it was detected. But Loeffler learned differently.

"When I first got there, I assumed it started back in 1969," he said. "But some time later, we discovered the fraud went back to 1964, when it issued its first annual report. In fact, it went back to the time when the company first borrowed funds. My opinion is that Equity Funding never made a profit."

Amazingly, Equity Funding's stock was, for a time just before the collapse, one of the favorites on Wall Street. And Stanley Goldblun, president, was hailed as a genius on the Street.

A total of 19 Equity Funding employees pleaded guilty to fraud charges, and most of them, including Goldblum, have gone to jail.

Asked why so many low-level employees went along with management in the fraud at Equity Funding as well as at other companies during that period. Loeffler blamed the easy morality of the times.

"Until Watergate," he said, "people didn't think of it as wrong. It was sort of like taking a drink during Prohibition - people didn't think much about it."

After cleaning out the worthless assets of Equity Funding, Loeffler was left with two healthy insurance companies, Bankers National Life Insurance Co. in Parsippany, N.J., and Northern Life Insurance Co. in Seattle.

Their assets were transferred to a new company, Orion Capital Corp., and on Oct. 12, with Equity Funding merely a shell, Loeffler resigned.

Creditors of Equity Funding will get from 12.3 to 80 cents for each dollar of claims.

Loeffler, who commuted on weekends to Minneapolis from Equity Funding's once lush headquarters, appropriately located on the Avenue of the Stars in Los Angeles, has now moved back to Minnesota.

Before going to Los Angeles, Loeffler had been senior vice president and general counsel of Investors Diversified Service, Inc., the huge Minneapolis investment fund.

He is not inclined to return to IDS, which he left at the restless age of 50 after eight years of employment. And the $1 million fee he received from the court for his Equity Funding effort make him relatively flexible on where he will be settle.

"It will be on one of the coasts," said his wife Marjorie.

As the former treasurer of Hubert Humphrey's recent re-election drive and a member of the National Finance Council of the Democratic National Committee, she would seem ready to cast her vote to move to the east coast, or more particularly, Washington.

Loeffler, for his part, is weighing all possible alternatives before setting out on a new career. The question of whether the chairmanship of the SEC will figure in Loeffler's deliberations should be answered in the near future when the White House announces its choice for the job.