Environmental Protection Agency official Louis J. Cordia, the focus of three congressional investigations into "hit lists" of agency employes and scientists considered liberal by industry groups, has been demoted and stripped of management responsibilities, it was learned yesterday.

Acting EPA Administrator John W. Hernandez ordered Cordia transferred from his job as deputy director of the Office of Federal Activities late Friday, after new accusations surfaced that he allegedly instructed a subordinate to erase computerized data requested by a newspaper reporter under the Freedom of Information Act, according to two administration officials.

The new charge was sent to White House Counsel Fred F. Fielding, who has reviewed accusations against other agency employes, and EPA Inspector General Charles L. Dempsey has been asked to investigate, the officials said.

Cordia did not return telephone calls, and the attorney he recently hired to represent him in the congressional probes, former representative Charles E. Wiggins (R-Calif.), could not be reached.

Cordia denied ordering the erasures, according to an EPA official.

In his new job, Cordia will work as an analyst in the agency's Office of Standards and Regulations, which develops rules on air and water pollution and other environmental threats.

"He will not have any management responsibilities at all," said an EPA official. "He will be a regular worker."

EPA spokesman Rusty Brashear said Hernandez characterized Cordia's reassignment as a "lateral move," although he had extensive management responsibilities in his former job.

In addition to the "hit lists" and the latest accusation, Cordia is also under scrutiny for allegedly attempting to remove 15 boxes of records from his office last month before being stopped by the inspector general's office.

The records, which Cordia called "background reference documents," are being reviewed by Dempsey's staff, the FBI and a House subcommittee.

Meanwhile, investigative subcommittees headed by Reps. John D. Dingell (D-Mich.), James H. Scheuer (D-N.Y.) and Mike Synar (D-Okla.) are reviewing Cordia's role in the preparation of lists detailing the political leanings of EPA employes and advisers as well as prospective employes.

The panels obtained the lists last month in the early stages of the EPA controversy.

Cordia has said he was "flooded" with such lists from industry and conservative groups when he worked on the Reagan transition team for the agency, shortly after leaving a job at the conservative Heritage Foundation.

But he has denied that the lists were ever used to penalize employes.

However, more than 50 scientists were removed from the agency's technical advisory boards after they were identified on one of the lists as "horrible," "a Nader on toxics," and a "bleeding heart liberal."

Dingell's panel is investigating to determine who prepared the lists and whether they were used to reassign civil servants viewed as unfriendly to the administration, according to an investigator.

In compliance with a subpoena, Cordia recently delivered to Dingell's panel several documents "evaluating or otherwise commenting upon" current or former EPA employes, contractors and consultants, the investigator said.

"It's not clear who prepared the lists, for what purpose or when," said a source close to the investigation. "The general nature of the comments are whether a person is or isn't compatible with the political philosophy of the EPA under the Reagan administration."