More than three-fourths of criminals convicted under the federal organized crime strike force program are receiving sentences of two years or less, and most are eligible for parole in no more than eight months.

Many of the cases handled by the program, which costs $100 million a year, "were not of a caliber" to warrant the expertise of such strike forces.

These are conclusions of a new study by the General Accounting Office that says "organized crime is flourishing" in this country. The Washington Post obtained a copy of the study.

The study also found little coordination among federal law enforcement agencies assigned to the task forces and in many cases improper use by the government of laws under which criminal assets and holdings can be attacked to "take the profit out of crime."

In a similar study four years ago, the GAO criticized government efforts to fight organized crime, and the new report concludes that many of the problems still exist. The current study covered cases closed between Oct. 31, 1977, and Dec. 31, 1979.

Sen. Max Baucus (D-Mont.), a member of the Senate Judiciary Committee who requested the investigation, said: "Despite all its tough talk, the federal government seems soft on organized crime . . . .

"Very few organized crime bosses ever spend any substantial time in jail . . . . Most people actually serving time in jail are eligible for parole after serving only one-third of their sentence, making jail little more than a minor inconvenience for the majority of those who participate in organized crime."

The Justice Department agreed with some of the criticisms and claimed that others were unfounded.

"Federal law enforcement efforts can deal only with one side of the organized crime equation," said Kevin D. Rooney, assistant attorney general for administration, in a written response.

"To the extent that the success of organized crime depends upon consensual crimes such as illegal gambling, narcotics, prostitution . . . it will continue to flourish as long as the American public continues its patronage of these income-producing activities . . . .Organized crime may persist in spite of our best and most successful efforts."

Members of the strike forces represent various federal law enforcement agencies, including the FBI; the Drug Enforcement Administration; the Bureau of Alcohol, Tobacco and Firearms; and the Internal Revenue Service, which provides expertise in financial aspects of the investigations.

The federal strike force concept was started in 1967, and 14 such forces are active in U.S. cities. The GAO study focused on those in Brooklyn, Chicago, Los Angeles and Philadelphia.

Of defendants prosecuted by strike forces during during the 14 months studied, only 22 percent were sentenced to terms of more than two years. The remaining 78 percent were paroled immediately or received sentences of two years or less.

The Justice Department provided information to the GAO indicating that during fiscal 1981 the average sentence had increased to 43 months. But 56 percent of strike force defendants still were receiving sentences of two years or less.

The GAO also found that for cases closed during the study period, strike forces had been pursuing cases that "were not of a caliber to warrant the expenditure of strike force resources" and that should have been transferred to U.S. attorneys for prosecution.

Of 180 cases closed by the four strike forces studied, 29 could have been transferred, the GAO said. Some examples included a counterfeit stamp case, a tool theft case and a fraudulent bankruptcy case, none with any connection to organized crime.

The Justice Department defended the strike force role in those cases, saying that generally they were spinoffs from major cases or attempts to turn defendants in smaller cases into witnesses for larger investigations.

Guidelines from the attorney general require each strike force to hold an executive committee meeting at least every two weeks to keep federal law enforcement agencies apprised of progress in investigations, but the four strike forces studied had not established executive committees.

The study concluded that the absence of the meetings contributes to lack of coordination and a tendency for too many cases to be dropped.

A sample of organized crime cases closed by the FBI, IRS, DEA and BATF during the study period found that 76 percent of the cases had been closed administratively or declined for prosecution by strike forces or U.S. attorneys.

"These cases were closed because they were not significant or prosecutable based on evidence developed or the limited potential for gathering more supportive evidence," GAO found, noting that until agencies coordinate activities and set specific organized crime targets, too many investigative resources will be spent on cases that never reach prosecution.

Only 23 percent of cases reviewed by GAO were prosecuted.

The Justice Department response indicated resistance to the idea of executive committee meetings and a belief that they "would not improve cooperation and coordination."

Another major complaint against the strike forces is that they have failed to use adequately the Racketeering Influenced Criminal Operation statute that allows fines of up to $25,000, sentences of up to 20 years and forfeiture of the assets of the criminal enterprise.

Much of the problem is with the statute itself, which leaves unanswered exactly what constitutes a criminal enterprise and how to go after assets laundered through a legitimate business or transferred to a third party. The Justice Department has said the law needs to be changed.

The GAO has recommended changes in the statute, and Sen. Joseph R. Biden Jr. (D-Del.), has filed such legislation in the Senate.