The agency charged with protecting federal workers from retribution if they report suspected corruption is steadily becoming more effective and has been unfairly criticized for siding with management, its head said yesterday.

In testimony before a Senate subcommittee, Special Counsel Mary Weisman rejected charges by whistle-blowers that her office offers little hope to employes who think their employers have penalized them for exposing fraud or waste.

"Part of the perceptual problems experienced by the office result from the fact that the Congress and the press generally only hear from disappointed complainants who do not qualify for relief from the OSC {Office of the Special Counsel}," Weisman said.

Her testimony came before the Post Office and Civil Service subcommittee on the federal services, which is drafting legislation to make the OSC more effective in protecting whistle-blowers.

The bill, sponsored by Sens. Charles E. Grassley (R-Iowa) and Carl M. Levin (D-Mich.), would reverse what critics of the OSC describe as a promanagement bias at the agency, which was created under the 1978 Civil Rights Reform Act. A House committee last week passed similar legislation.

"The fact is that during the Reagan administration, the Office of the Special Counsel -- the whistle-blower's safe harbor -- seems to have acquired a reputation for being decidedly antiwhistle-blower," said subcommittee Chairman David H. Pryor (D-Ark.), adding that "former Reagan appointees to the job {of special counsel} have appeared more interested in burying whistle-blowers than in helping them."

Weisman, who has been head of the OSC for almost a year, said the agency has become more aggressive in defending federal employes. She said that under her leadership the agency has won six of nine whistle-blower cases it has taken on and expects to prevail in two of three pending cases.

Two other witnesses, however, charged that the OSC has been totally ineffective and proposed alternative ways of addressing whistle-blower grievances.

Loebe Julie, president of the Coalition to Stop Government Waste, told the committee that honest whistle-blowers should be guaranteed immunity from punishment and assured the right to hearings of their cases through arbitration.

Charging that the OSC's main duty has been to "blacklist rejected reprisal victims," Thomas Devine, legal director of the Government Accountability Project, suggested a list of modifications to the bill, including one that would abolish the OSC or establish a system of judicial review to contest "arbitrary and capricious" OSC conduct.