The Securities and Exchange Commission yesterday brough its first action against a brokerage for alleged irregularities in selling stock opinions.

In a nonjudical proceeding, the SEC charged Bache Halsey Stuart Shields Inc. and four former and present employes with civil fraud for allegedly churning, or unnecessarily trading, customer accounts to generate commissions.

In addition to Bache, the commission named David Lambert and John Genetti, formely employed at the brokerage's offices at Columbia and Myrtle Beach, S.C., and South Bend, Ind., respectively.

The SEC also named their supervisors - Francis Moise, who managed Bache' Columbia-Myrtle Beach offices, and Richard Clary who headed the South Bend office. The managers, who still are employed by Bache, were charged with failing to "reasonably supervisor" Lambert and Genetti.

A stock option is a contract to buy or sell a specified number of shares of a traded security at a given price within a specified period of time. One reason for the popularity of options trading is that, at least initially, a relatively small amount of money is neededto trade options. This is because the customer puts up a percentage - or margin - of the price of the transaction, borrowing the rest from the broker.

In 1977, the Chicago Board Options Exchange, which handles about 50 percent of the trading volume of the five options markets currently operating, reported options trading on 2.2 billion shares of stock. Exchange trading in options began on a limited number of stocks in April 1973, and the SEC recently halted adding new stocks until it completes a massive study of options trading.

In a statement issued by its New York headquarters, Bache called the 1975-1976 transactions "isolated occurences," adding that it settled without admitting or denying the SEC allegations.

Bache also noted - and an SEC source confirmed - that "there are currently pending investigations against several other major brokerage firms with respect to options transactions."

Bache, Lambert and Genetti, caused customers who could not afford the risk and did not sufficiently understand the risk . . . to believe they would be dealt with fairly," the SEC charged.

According to the SEC, Bache issued at least 71 margin calls totalling at least $2.4 million on Lambert's personal account and those of four of his customers.

Margin calls are issued when the market moves against the customer's position. The broker is asking the customer for an increased margin to cover the changing position.

"Lambert generally failed to advise customers of such margin calls," the SEC said. When notices were sent to the customers, Lambert allegedly told them that the calls "were erroneous and should be disregarded."

The SEC said that Bache, acting on Lambert's orders, got unwarranted extensions on the margin calls from the New York Stock Exchange. "Certain of Lambert's customers were not aware of their mounting losses," the SEC said.

As part of the settlement, Bache agreed to reimburse more than $94,000 to present and former options customers involved in the transactions. Bache also agreed to forgive nearly $263,600 in options-related claims against these customers' accounts.

Bache agreed not to take on any new options accounts at its offices in South Bend and Columbia for 45 days. Moise was barred from taking any supervisory job at a brokerage business SEC approval, and Cleary was suspended from the brokerage business for 15 days. Genetti agreed to stay out of the securities business for two years.

According to an SEC spokesman, Lambert, the other broker, has not yer settled with the commission.