In response to sweeping federal subpoenas for hundreds of hours of videotape of the TWA hostage crisis, three of the four national television networks agreed yesterday to provide at least some access to their tape libraries for government investigators preparing a criminal case against the hijackers.

ABC, NBC and Cable News Network announced that they would make all videotape shown on the air available immediately, as the Justice Department tries to identify and charge the three original hijackers, who are still at large, possibly in the Middle East. The department issued subpoenas Tuesday for all of the four networks' videotapes of the hijack incident in an unusually broad attempt to use network files for a criminal investigation.

On the sensitive issue of whether the government should be allowed to see "outtakes," tapes not shown on the air, the three networks have also worked out what one government official called an "understanding" that footage crucial to the case can be screened by government investigators at network offices, according to network and government sources.

A spokesman for CBS said late yesterday that network officials would have no comment on their subpoena until CBS lawyers meet with Justice officials, possibly today.

Sources said Justice wants to present the network footage to a federal grand jury now sitting in Washington for use as evidence or to help track down witnesses for the hijacking of Trans World Airlines Flight 847 that resulted in the murder of one American, Robert Dean Stethem of Waldorf, Md., and the detaining of 39 American men for 17 days.

Attorney General Edwin Meese III has said the government will do anything it can legally to bring the hijackers to trial in this country. During a recent press briefing, he did not rule out the possibility that they could be kidnaped and brought to trial in the United States.

Legally, the Justice Department would have to make an extradition request to authorities in the country where the hijackers are located. The United States has no extradition agreement with Lebanon or Syria, however.

Justice spokesman John K. Russell said the networks were subpoenaed because "we need the identity of one individual hijacker. We know who they are. We have to get a visual, . . . a positive identification."

Russell, acknowledging that outtakes were the major sticking point for network officials, said: "The networks are under heat in this hijacking thing to be cooperative. The public sentiment is on our side."

Robert R. Siegenthaler, vice president for news practices at ABC, said the government request complies with company guidelines written in 1982 that allows ABC to consider cooperation with government agencies when there are threats to human life, considerations of national security and the need for information about a crime that has been committed or is about to be committed.

"What we've done in this case is comply with our guidelines. We believe that national security and the crime question . . . are relevant. Our attorneys have talked to Justice Department attorneys, and it's our understanding that the scope of the inquiry is criminal . . . ."

"There won't be carte blanche given, but we'll do our best to comply with our responsibilities both to good journalism and good citizenship," Siegenthaler said.

NBC Vice President Timothy J. Russert said that the network will do an internal review of footage not aired during the crisis "and if any information is deemed relevant to the Justice Department investigation of crimes of air piracy or murder, we will provide them screening opportunity."

CNN released a statement yesterday that it would honor a request for videotapes of "published and unpublished material covering the hijacking itself, hijackers, guards, negotiators, the hostages themselves and all interviews" because "providing the requested material is in the public interest."

However, Ed Turner, CNN's executive vice president, said, "This is a first and it makes me nervous . . . . I don't want this considered too much of a precedent by Uncle."

He added later: "The dangerous part of all this is the recognition by terrorists that the camera lens could become a witness for the government and create even more danger than exists already for camera crews or still photographers on the scene.

"The government would have been far wiser to have handled this in a quieter way," Turner said.

However, Justice officials said that network officials had indicated in preliminary talks that they were willing to hand over much of their hostage videotape, but that they preferred that the government demand it by subpoena rather than to provide the footage voluntarily.

Media lawyers and network sources said yesterday that such a request would be difficult for the networks to turn down because the Supreme Court ruled in 1972 that reporters could not refuse to provide information to grand juries concerning a crime or the sources of evidence of a crime.

One network executive said that the screening of tape for government officials has been done unofficially for such televised events as the assassination attempt on President Reagan and events surrounding the assassination of public figures such as the Rev. Martin Luther King Jr.

"But we are deeply concerned about this, that if this is done routinely, there are grave consequences," the executive said, referring to the possible use of subpoenas to intimidate news organizations.

During the Carter administration, the Justice Department set up guidelines for asking news organizations to hand over tape, notes or information for grand juries. The guidelines, which Justice officials said were complied with for these subpoenas, require that the information be available from no other source and that the demands for information be approved by the attorney general or his designate.

Several network officials said that one of their problems is trying to work out the logistics of getting tape in one place. James A. Rutledge, assistant chief of CNN's Washington bureau, said that from CNN alone, there would be at least 600 hours' worth of footage.

"I don't think they realize what they're asking for," Rutledge said. "The Justice Department could be looking at this stuff for 25 years."