A federal grand jury in Baltimore yesterday indicted four men for conspiracy to defraud the General Services Administration and outlined a complicated scheme in which one of the men allegedly fenced equipment for cash used to bribe GSA employes.

The equipment included tractors, televisions, chain saws and typewriters purchased through department store charge accounts that were set up by a Maryland office supply company for the purpose of paying bribes to GSA employes, the indictment said.

One of the men named in the indictment, Matthew Smith, 54, of Washington, identified by a government prosecutor as a friend of those employes, later sold the equipment and split the cash proceeds with the employes.

In a separate indictment, the grand jury charged Robert D. Keegan, 39, the owner of Keegan's Appliances in Washington, submitted bills for nonexistent merchandise to the same Maryland company in order to generate cash for bribes.

Two other men, Dennis Keefer, 57, of Arlington, and William H. Anderson, 31, of Washington, both GSA employes, were also charged in two additional indictments with certifying they received office supplies from the Maryland company that was never delivered.

Officers of the Maryland company, Hilles Associates, located in Westminster, Md., have previously testified that they bribed GSA employes so that Hilles would be paid by GSA for goods that were never received.

The president and executive vice president of Hilles have pleaded guilty to fraud charges in U.S. District Court in Baltimore. Two other Hilles' employes have testified in previous GSA trials that they handled the paper work for paying GSA-connected bribes.

Until recently, Anderson and Keefer were assistant managers at GSA office supply stores. They had been promoted by the agency to replace GSA employes who had previously been indicted in connection with a continuing federal investigation into GSA contracting practices.

GSA suspended Anderson and Keefer yesterday following their indictment.

According to the indictment, Keefer allegedly received $4,000 in cash bribes from Hilles for his role in the scheme. Anderson allegedly received a television set and trash compactor, the grand jury said.

Keegan, the appliance store owner, generated $12,000 in cash to be used to bribe GSA employes, according to yesterday's indictment.

In previous court testimony, Hilles' officers have said that Keegan received a 3 percent commission on the amount of cash he paid to the GSA employes.

In an additional indictment yesterday the grand jury also charged Matthew Smith with bribing GSA employes to certify they received office supplies from his three Maryland supply firms, although the items were never delivered.

Evidence in the case was presented to the grand jury by Assistant U.S. Attorneys Daniel M. Clements and Elizabeth H. Trimble. So far, 45 individuals have been indicted in the GSA investigation and 38 of them have pleaded guilty or been convicted after jury trials.

The first sentencings in the cases are scheduled for next week in Baltimore federal court. This week Clements recommended a sentence of 15 months in the case of Hugh S. Smith, 42, a GSA office supply supervisor who has pleaded guilty and is cooperating in the probes.