The Justice Department, ending weeks of uncertainty about whether or not it would proceed with the prosecution of two former FBI officials charged with approving illegal breakins, turned over scores of government documents to defense lawyers yeaterday.

In a letter to U.S. District Court Chief Judge William B. Bryant, Justice Department prosecutor Francis J. Martin said that the government was "voluntarily" turning over documents sought by lawyers for W. Mark Felt, once the FBI's second in command, and by Edward S. Miller, the bureau's former intelligence chief. Defense lawyers, Martin said, "are fully informed so as to be able to proceed with preparation for trial."

The defense lawyers sought classified materials held by the Central Intelligence Agency and other government agencies that they claimed were relevant to their case. Both lawyers, Brian P. Gettings for Felt and Ghomas A. Kennelly for Miller said they would have to examine the documents before knowing whether their requests had been satisfied.

Martin's letter anticipates "that some disputes will remain as to the adequacy of the government's compliance" with Bryant's order to turn over relevant documents and that the judge will have to examine some documents himself to determine whether they must also be turned over to the defense.

The documents turned over yesterday involve only the government's case against former acting FBI director L. Patrick Gray III has been severed from the charges against Felt and Miller. All three are charged with conspiring to violate the civil rights of friends and relatives of members of the Weather Underground in the early 1970s by allegedly approving illegal break-ins of their homes.

Gray has denied giving such authorization, while Felt and Miller claim that they approved the burglaries on Gary's authority.

In his letter to Bryant yesterday Martin said that the FBI, the CIA and the National Security Agency "have all realased substantial amounts of information that had previously been withheld." Martin said that some documents that had raised defense objections when released in an edited form now were being released "substantially" unedited.

The government's action yesterday appears to remove doubt concerning trial of the charges against Felt and Miller. Prosecution of Gray remains in doubt since the issues involving him are of greater magnitude for the government.

No trial date has been set by Bryant for Felt and Miller.