The Securities and Exchange Commission has linked a group of Brooklyn investors to a Swiss brokerage firm that figures in the largest insider trading investigation ever undertaken by the federal agency.

The SEC named Berel and Sarah Light and "many individuals residing in the Boro Park section" of Brooklyn as purchasers of the same securities as Ellis A. G., a Zurich securities concern that purchased common stock and options in more than 40 companies shortly before news of takeover attempts involving those companies became public. The disclosure was in papers filed Dec. 1 by the SEC in U.S. District Court in New York.

The Wall Street Journal has quoted sources close to the case as saying that the SEC believes illegal profits resulting from those trades amounted to more than $40 million. Insider trading on non-public information violates securities laws.

According to court documents, Ellis purchased, either for its account or for customer accounts, common stock and call options for common stock in U.S. companies that became takeover targets between October 1981 and when the investigation began in late 1983. Furthermore, the SEC alleges that Ellis and Berel Light, described as "an active securities trader who maintains numerous brokerage accounts with several brokerage firms," bought the same securities at least 10 times, starting in June 1983. In seven of those cases, annoucement of a tender offer followed the purchases by a few days and the stocks appreciated.

For example, Ellis bought Carter Hawley Hale Stores Inc. stock on March 15 and Light bought it 14 days later. On April 3, Limited Stores Inc. announced a tender offer for Carter Hawley Hale. The same thing happened with the stock of Jewel Cos. Inc. before American Stores Co. announced a business combination.

"These facts suggest to the commission that Mr. Light may have been acting in concert with Ellis, with persons trading through Ellis, and with others," the court papers said.

The other takeover targets in whose stock the SEC alleges Ellis traded include Itek Corp., Instrumentation Laboratories Inc., Fred S. James & Co., Crum and Forster, Criton Corp., Heublein Inc., Dyneer Corp., Kallestad Laboratories Inc., StaRite Industries Inc., Burns International Security Services, Schlitz Brewing Co., Life Investors Inc., Questor Corp., Hanna Mining Co., Marathon Oil Co., and Dean Witter Reynolds Organization Co.

The commission's information came to light when the SEC responded to a motion by the Lights to quash subpoenas served by the SEC on their banks -- Citibank and Israel Discount Bank of New York. The SEC contends that these bank records are very important to its investigation and may help it to determine whether Light and others paid or received money in exchange for receiving or providing information about the securities in question. The Lights, from Fairlawn, N.J., previously lived in Boro Park. They have not been charged with any securities violations.

In that response, the SEC noted that the bank records were necessary because, "as a result of Swiss confidentiality laws, the commission has been hindered in its efforts to obtain information about Ellis and the unknown purchasers on whose behalf it has traded." More than 20 individuals are said to be under investigation.