The 12 present and former General Services Administration office supply store managers indicted yesterday are mostly middle level, middle-aged government employes who live in the Washington suburbs and earn between $14,800 to $18,100 a year each.

Many of them could be reached for comment yesterday, and others referred callers to their attorneys.

One of them, Johnnie J. Sykes, 32, of Oxen Hill, said he was unaware of his indictment. "I* 've been working all day and I don't know anything about it," he told a reporter and then hung up. Sykes, who has left GSA, is now employed by the Environmental Protection Agency.

One of those indicted, LaVerne E. Gildner Jr., the manager of GSA's office supply store in Philadelphia, came to work for GSA after serving in Vietnam, according to his lawyer. Gildner is a GS-9, who earns $15,090 a year. He worked in supply for the Navy before leaving the Navy four years ago, said Gildner's lawyer, Bernard V. O'Hare of Philadelphia.

Eugene F. Proctor, 50, of Washington who works as a supply clerk at the Navy Department's Bureau of Medicine and Surgery in Arlington, said he had worked there since 1950 and was a graduate of Phelps Vocational High School. When Proctor was asked if he knew why he was indicted yesterday, he said, "Yes, I know why," but refused further comment.

"I'm upset and shocked," said Donald E. Wheeler, 47, of Clinton, who has worked for 18 years as a supply clerk for the land and natural resources division of the Justice Department. Wheeler said he was surprised by news of the indictment and knew nothing about it except what he had been briefly told by a reporter who contacted him.

The other indicted GSA employes are Raymond Henley, 46, of Landover, who earns $17,605 a year; William H. Jordan, 45, of Washington, $16,599; Charles C. Lee, 45, of Woodbridge, $17,102; Wilmont E. Peters, 49, of Alexandria, $18,108; Charles E. Phelps, 39, of Upper Mariboro, $16,096, and Robert M. Rawes, 58, of Lanham, $17,605; Eugene D. Shadle Jr., 36, of Waldorf, Md., $14,802; James I. Taylor, 44, of Washington, $14,802; Roger D. Wilt, 29, of District Heights, $16,096, and William E. Eason, 62, of Washington.

In addition to Proctor and Wheeler, the non-GSA employes indicted were Samuel L. McClain, 46, of Hanover, Md., and Sterling T. Johnson Sr., 56, of Severn, Md., both of whom work at Fort Meade.

The office supply firm executives indicated were H. David Levyne, 44, of a Clarksville, Md., chairman of the board and president of Hilles Associates Inc. of Maryland, and Charles H. Oertel, 55, of Washington, who is vice president of Hilles. The Hilles corporation sold administrative and industrial supplies and goods to GSA, according to the indictment.