Representatives of several government agencies are scheduled to meet today to coordinate their investigations of the spreading scandals within the General Services Administration.

Vincent R. Alto, a former Justice Department prosecutor hired by GSA Administrator Jay Solomon to supervise GSA's own investigations, called the conference to obtain assistance in looking into areas already under investigations as well as new areas, sources said.

The meeting is to include representatives of the Internal Revenue Service, Securities and Exchange Commission, U.S. Postal Service inspection service, and the civil and criminal sections of the Justice Department, in addition to GSA's office of investigations.

The FBI already is heavily involved in the investigations, which have established that millions of dollars have been paid for services or goods never provided GSA.

Law enforcement sources saw the meeting as a sign that infighting among various agencies investigating the GSA scandals may be on the wane.

Last week, Sen. Lawton Chiles (D-Fla.), chairman of the Senate Governmental Affairs' federal spending practices subcommittee, charged that some federal officers were spending more time fighting among themselves than investigating criminals.

He called for a meeting with the Justice Department to develop guidelines to reduce friction and threatened to disclose the names of those involved in the disputes.

Chiles is scheduled to meet today with Attorney General Griffin Bell.

Over the past few months, GSA has complained to the Justice Department that the U.S. Attorney's office and the FBI here were not pursuing the GSA investigations as aggressively as GSA would like. Those agencies, in turn, countered that GSA has not been fully cooperating with them.

Law enforcement sources see the dispute as presaging problems likely to arise when each government agency later this year appoints an inspector general to conduct internal investigations.

What has yet to be worked out, sources say, is a question of when internal investigators should turn their findings over to the Justice Department and the FBI.

At GSA, internal investigators have complained that turning allegations over to the FBI in the past has meant that nothing ever came of them. They have maintained that they are often better equipped to handle complicated matters within their own agency because they are familiar with GSA and may have a more personal interest in pursuing the cases.

As a result, they say, they should be able to develop cases more fully before turning them over to prosecutors.

The FBI and prosecutors, on the other hand, have said it was unlikely that GSA investigators would have been allowed in the past to uncover serious wrongdoing because of pressures from within the agency.

As a rule, they have said, internal investigators are more likely to be in league with those being investigated than outside probers and may jeopadize chances for successful prosecutions because they are less familiar with proper way of handling evidence and witnesses.

Therefore, according to this argument, prosecutors who might eventually try a case should supervise it from the outset.

"You have a legitimate quandary here," a source said, "and it's going to have to be hammered out over the next few months."