The Securities and Exchange Commission was criticized in Senate hearings yesterday for failing to alert the Commodity Futures Trading Commission to heavy trading in futures contracts by former stock speculator Ivan F. Boesky.

Much of Boesky's trading took place after he had secretly reached his record $100 million insider trading settlement with the government last September, but before the deal was announced in November. Sen. Patrick J. Leahy (D-Vt.) said the SEC should have notified the CFTC of the settlement so that Boesky's trading could have been monitored.

Leahy said the futures trading involved hundreds of millions of dollars of securities.

CFTC Commissioner William Seale said that based on Boesky's futures trading records, "There is no indication ... of some incredible profiteering."

The SEC has said that Boesky did not violate laws by trading stocks before his case was disclosed, but Sen. Richard Lugar (R-Ind.) said the disclosures of Boesky's trading raised ethical questions. "What we are looking at is the ethical problem of whether someone ought to be able to run into the futures market and continue his trading," Lugar said.

The SEC did not share information about the Boesky probe with the CFTC, which is responsible for monitoring all futures trading, including the booming markets in futures contracts on stock indexes.

CFTC Chairman Susan Phillips told the Senate Agriculture Committee that the SEC notified her agency of the Boesky probe about an hour before the settlement was announced to the public last Nov. 14.

"The point is there is cause for concern in the SEC not coordinating with you in this matter," Leahy told Phillips and the other four CFTC commissioners who testified yesterday. "The SEC went after this as if their only concern was the markets under their jurisdiction."

SEC enforcement chief Gary Lynch defended the decision not to alert the CFTC to the Boesky settlement in advance. Lynch said in an interview that there were "very strong law enforcement interests" in keeping the deal with Boesky a secret.

As previously reported, Boesky tape-recorded conversations with his Wall Street colleagues in the months before the announcement of his case. If information about the Boesky settlement had leaked out, the government would not have been able to take maximum advantage of Boesky's cooperation as it pursued evidence of other Wall Street corruption, sources familiar with the investigation said.

"It is absolutely clear that to the extent you expand the circle of people who know information, whether it is merger and acquisition discussions or a proposed law enforcement action, there is more potential for leakage," Lynch said.

The SEC has been criticized previously for allowing Boesky to sell off hundreds of millions of dollars of stock prior to the announcement of charges against him. Disclosures this week that Boesky also traded futures contracts worth millions of dollars during this period have rekindled the controversy.

The SEC has said that it permitted Boesky to sell the stocks in advance of the announcement because it was afraid that a market panic could ensue if Boesky were forced to dump billions of dollars of stock after the case against him was announced. Sources have said the SEC did not focus on Boesky's futures trading during this period.

Wall Street speculators known as arbitrageurs, some of whom suffered heavy losses when stocks plunged in the days after the Boesky case was disclosed, have criticized the SEC decision. They refer to the Boesky stock sell-off as his last great insider trading, arguing that he was allowed to profit from confidential information about his own demise. They reacted similarly yesterday to news that Boesky had a large "short" position in stock index futures.

Boesky's stock and futures trades were executed on behalf of a group of investors, including himself. By selling in advance of the announcement of the charges against him, Boesky attempted to maximize the value of the stocks and the futures contracts under his control, thereby minimizing his future legal liability.

Boesky is the subject of a civil lawsuit filed by many of those who gave him their money to invest in stocks of takeover targets. The lawsuit was filed after the government charged Boesky with trading stocks on the basis of confidential information about corporate takeovers.

Based on details of Boesky's futures trading that emerged at the hearing yesterday and information from sources who have reviewed Boesky's trading records, it appears he may have used futures contracts as a hedge to minimize the risk of losses in his giant stock portfolio in the event of a stock market decline.

Boesky also could have been using futures contracts on the Standard & Poor's 500 Index and the New York Composite Index to speculate on the direction of the stock market. The sale of a large block of stocks like Boesky's can depress prices.

Prior to the announcement of the charges against him last November, Boesky had a substantial "short" position in the contracts, which means he was anticipating a stock market decline. CFTC Chairman Phillips said it appeared that Boesky made a modest profit by closing out some of these contracts just after announcement of the charges against him.

A letter to Leahy describing Boesky's trading, written by Phillips, raises questions about whether Boesky was trading futures contracts to hedge his stock portfolio or for other purposes.

"While the commission has no information on the size of any stock portfolios that Mr. Boesky owned, as a major risk arbitrageur we would expect him to have substantial long stock positions," Phillips wrote.

"Short futures positions could have been used to hedge those stock positions from the risk of a broad decline in stock prices. However, if Mr. Boesky's stock holdings were heavily concentrated in stocks that were potential merger targets, short futures positions in indices like the S&P 500 and the NYSE Composite may not necessarily have provided good price protection from the risks associated with owning those stocks."

Boesky concentrated his investments in the stocks of companies involved in mergers.

After the charges against him were announced last November, Boesky participated in the selling off of his remaining stock portfolio. He also regularly adjusted his futures positions, sources said, based on the size of his stock portfolio and his view of the future direction of the market.

Boesky's attorneys declined comment.