Published: April 10, 1987

A Federal grand jury yesterday indicted three senior Wall Street traders who had been arrested in February on charges of insider trading.

The three, Robert M. Freeman, 44 years old, director of arbitrage at Goldman, Sachs & Company; Richard B. Wigton, 52, head of arbitrage at Kidder, Peabody & Company , and Timothy L. Tabor, 33, a former arbitrage trader at Kidder, Peabody, were each charged with four felony counts. The long-awaited charges included conspiracy to commit securities, mail and wire fraud and three counts of having committed securities fraud.

Through their lawyers, each denied the charges in the indictment, obtained by the United States Attorney in Manhattan.

A number of lawyers involved in the case, criminal law experts and Wall Street executives said they were struck more by what was not in yesterday's indictment than by what was included. The nine-page document repeats much of the information in the original complaint filed at the time of the traders' arrests, but it contains less information, in several respects, than that complaint. No Other Stocks Mentioned

No new stocks were identified as the subject of the insider trading. As in the complaints, the only stocks mentioned were of the Unocal Corporation and Storer Communications Inc., and there was no reference to the Continental Group Inc.

Martin A. Siegel, a former Kidder, Peabody investment banker, previously pleaded guilty to a charge that he had received an inside tip about Continental from Mr. Freeman, and then had Kidder, Peabody profit from trading in its stock.

In subpoenas issued to the firms after the arrests, the Government sought information about more than 40 companies that had been involved in takeovers or were clients of the firms, sources with knowledge of the investigation have said. The sources said that subpoenas were also issued to individuals at each of the firms.

In a search warrant obtained to collect records from Mr. Freeman's office in February, the Government also alleged that Mr. Freeman told Mr. Siegel he had created ''padded'' research files on stocks in which he traded illegally, so it would appear that the trades were based on legal information.

'From what I know there is substantial material that could be used to impeach Mr. Siegel's testimony,'' said Andrew Lawler, Mr. Tabor's attorney. ''We intend to enter a plea of not guilty and to aggressively litigate.''

According to the indictment, from June 1984 to January 1986 Mr. Siegel swapped tips with Mr. Freeman about pending takeover transactions on which their firms were working. Secret Details on Storer

Mr. Siegel reportedly leaked secret details of a takeover involving Storer Communications to Mr. Freeman. Mr. Freeman is said to have then traded with that information, earning unspecified profits for himself, his family and Goldman, Sachs.

In turn, Mr. Freeman is said to have tipped off Mr. Siegel about a takeover bid involving Unocal, a Goldman, Sachs client. Mr. Siegel is said to have passed this information to Mr. Wigton and Mr. Tabor, who used it to earn unspecified profits for Kidder, Peabody.

''Mr. Freeman will plead not guilty, and we look forward to going to trial,'' said Paul J. Curran, Mr. Freeman's attorney.

''Mr. Wigton will be found innocent,'' said Stanley Arkin, his attorney. Kidder, Peabody suspended Mr. Wigton without pay yesterday, pending a trial, the company said.

Mr. Freeman remains a partner at Goldman, Sachs. Sources close to the firm said that since his arrest he had been spending most of his time helping to prepare his defense.

Mr. Tabor is currently unemployed.

photo of Robert M. Freeman; photo of Richard B. Wigton; photo of Timothy L. Tabor

Neither Kidder, Peabody nor Goldman, Sachs was charged in yesterday's indictment, despite the Government's allegation that they had profited from the trading.

An arraignment of the three traders was set for next Thursday in Federal District Court in Manhattan. Would Be First Insider Trials

The lawyers for the indicted traders said that they planned to fight the charges in court and insisted that their clients would be vindicated. Their responses indicated that the Government might face its first trials since the scandal blew up last May with the arrest of Dennis B. Levine, a former investment banker at Drexel Burnham Lambert Inc. Up to now, 10 investment bankers or lawyers have pleaded guilty to felony charges or agreed to do so, without one case having gone to court.

The indictment had been expected since the three were dramatically arrested, shocking Wall Street and heightening the nervousness created by the spreading scandal.

Mr. Tabor was arrested at his Manhattan home late on Feb. 11 and Mr. Freeman and Mr. Wigton were taken from their offices on Feb. 12.

ll had been implicated by Mr. Siegel, a former senior investment banker and takeover specialist at Kidder, Peabody. He pleaded guilty on Feb. 13, the day after Mr. Freeman and Mr. Wigton were arrested. He also settled Securities and Exchange Commission charges that he had sold inside tips for $700,000 to the arbitrager Ivan F. Boesky. Siegel Only Known Source

In its original complaint, the Government hinted that its charges had resulted from information provided by sources in addition to Mr. Siegel, although it did not identify the sources. Nor did the indictment issued yesterday refer to any other potential witnesses. The defense lawyers involved indicated that they looked forward to cross-examining Mr. Siegel, should he be a key Government witness.