Neither the White House nor the Senate has demonstrated a sustained commitment to "high quality" federal regulatory agency appointments during the past 15 years, according to an 18-month investigation by the Senate Government Operations Committee, made public yesterday.

Persons named to the regulatory bodies by Republican and Democratic presidents frequently are ill equipped for their jobs and a comparatively large number come from regulated industries, "which is in sharp contrast to the rare selection of persons with clear identification with public interest group concerns," the Senate report concluded.

Sen. Abraham M. Ribicoff (D.-Conn.), chairman of the committee, said the study also demonstrated that the Civil Service Commission and the federal agencies themselves had failed to enforce conflict of interest laws and regulations.

Details from the first two volumes of the report and 64 specific recommendations for remedial action will be presented to a hearing of the Senate committee scheduled this morning. Four additional reports are planned during the next two months from what Ribicoff and Sen. Charles H. Percy (R-Ill.) called the "most comprehensive" study of regulatory agencies ever undertaken by Congress.

As part of the study, practicing lawyers before nine major commissions and administrative law judges were asked to assess - anonymously - the agencies' performance. Respondents to the survey said less than two-thirds of the commissioners even understood the laws they were asked to administer.

The lawyers gave particularly high marks to the Securities and Exchange Commission but said that for all other agencies they couldn't recommend reappointments for about half the various commission members.

Lawyers gave the SEC the most favorable ratings of judgment, technical knowledge, impartiality, legal ability, integrity and hard work. For two agencies - the Federal Maritime and Federal Trade Commissions - the lawyers said they could recommend reappointments for less than 40 per cent of the members.

Respondents to a Senate staff questionaire said they did not believe there had been much change in the quality of commissioners over the years and most of the practicing lawyers identified delay as the greatest problem facing the public.

The Senate staff, meanwhile, found that more than half the agencies studied had not taken steps to establish mechanisms for compliance with conflict of interest laws that apply not only to commissioners but staff personnel.

Commissioners named by presidents and ratified by the Senate are mainly white male lawyers; women, minorities and persons with backgrounds in economics, engineering, political science, accounting and other professions generally have been ignored, the study said.

The "lack of balance" on agencies was described in the report as a "major concern," with seven women and four blacks appointed to nine large commissions since 1961, out of more than 150 appointments.

As a consequence, "too often the overall composition of the commissions have been heavily weighted in the direction of a single approach or a point of view," yesterday's report stated.

To correct such abuses, the Senate staff recommended enactment of "sunset" legislation, to put every agency out of business on a given date unless specifically continued by Congress.

Such legislation was introduced earlier this week by Ribicoff, Percy, and Senate Majority Leader Robert C. Byrd (D-W. Va.). The bill sets forth a timetable by which, over eight years, the President would submit to Congress regulation reform legislation every two years dealing with specific sectors of the economy. Energy, the environment, housing, occupational health and safety would be the first areas considered.

Among other specific recommendations made yesterday were the following:

For a period of one year, former regulators would be prohibited from having any contact for financial gain and compensation with the agency or its employees, on matters pending before the agency. For specific cases before an agency in which regulators participated, the prohibition would apply for life.

Standards should be established to govern enforcement of conflict of interest situations, financial statements of nominees and public inspection and formation of blind trusts for nominees' investments.

The 11-member interstate Commerce Commission should be reduced to three members with the President raming three members for the newly constituted body.

Legislation requiring that commissions represent broad interests and a variety of backgrounds should be enacted.

The President should be given unquestioned authority to appoint chairmen at the Civil Aeronauties Board, Federal Power Commission and Consumer Product Safety Commission.

Many of the conflict of interest rules proposed yesterday already have been adopted by President Carter for his appointees, but the Carter guidelines are not low. To date, Carter has not made any nominations to the various regulatory commissions.

In a separate development yesterday, a group called the "committee for an effective Federal Trade Commission" urged Carter to remove from consideration three persons reportedly being studied to head that agency.

The committee told Carter, in a letter delivered to the White House, that Senate Commerce Committee counsel Michael Pertshuck and lawyers Robert Pitofsky and Joan Bernstein were more interested in protecting interests of concentrated industries "than the social and economic needs of the nation's consumers."

Individuals who signed the letter were Henry Etzkowitz, associate professor at the State University of New York at Purchase, N.Y.; Edwin Rothschild, former executive vice president of the American Public Gas Association; and G. Willam Domhoff, assistant professor at the University of California, Santa Cruz.