The Carter administration yesterday agreed to double the number of federal employees who enforce civil rights laws and to take major new steps to end discrimination in all levels of education.

The agreements were included in a settlement of three long-standing lawsuits approved by U.S. District Court Judge John H. Pratt.

They commit the Department of Health, Education and Welfare to hiring 898 new employees in its Office for Civil Rights, eliminating a backlog of 3,000 complaints of discrimination and beginning major civil rights investigations of universities and school districts.

Attorneys for the four groups which brought the suits called the settlement a "landmark."

"This is really a great step forward for civil rights," said Joseph L. Rauh Jr., who worked on the suit in behalf of the NAACP Legal Defense Fund. "This will put a burr under the administration's tail to enforce civil rights laws. Up until this point, they've moved very slowly."

"The practical effect for sex discrimination cases will be enormous," said Marcia Greenberger, an attorney of the Center for Law and Social Policy, which represented the Women's Equity Action. "It requires HEW to become serious about sex discrimination."

[WORD ILLEGIBLE] other two groups bringing suit [WORD ILLEGIBLE] -American Legal Defense and Educational Fund and the National Federation for the Blind.

The suits accused HEW of doing little or nothing to end discrimination on the basis of sex, race and physical handicaps in educational programs paid for with government money.

The cases, the oldest of which dates back to 1970, were originally brought against the Nixon and Ford administrations. But the Carter administration also contested them until recently.

In announcing their conclusion, HEW Secretary Joseph A. Califano Jr, praised the groups that brought the suits, and said the settlement "is in the best interest of all those who are victims of discrimination and who stand to benefit from an aggressive civil rights enforcement effor tby this administration."

The suits, he told a news conference, were brought against HEW because it had failed to pursue legitimate complaints of discrimination. "Many of those complaints were ignored . . . or were shelved without a review, and the victims of discrimination did not receive the protection they deserved from the federal government," Califano said.

Under the settlement, the administration pledged to clear up a backlog of 3,000 discrimination cases by Sept. 3, 1979, and agreed to extend a timetable, set earlier by Pratt for 17 southern and border states, to the entire country.

The agreement covers racial discrimination, sex discrimination banned by Title IX of the 1972 Education Amendments and discrimination against handicapped persons prohibited by Section 504 of the Rehabilitation Act of 1973.

It also allows HEW to make broad reviews of discrimination practices in school districts, colleges and universities. Little of this has been done in recent years because HEW has committed most of its resources to handling individual complaints.

In other matters, Califano said he is unclear about a new abortion law and has asked HEW lawyers to determine whether it means victims of rape and incest can easily get government money for abortions. But in the meantime, he said, "no one in the government can answer" questions from doctors, hospitals and clinics about abortion financing.

Sen. Edward W. Brooke (R-Mass.) and Warren G. Magnuson (D-Wash.) have been extremely critical of Califano on this matter. The secretary yesterday sent both of them letters saying they misinterpreted him when they accused him of misinterpreting Congress' intent on abortion funding.

Califano, who is personally opposed to abortions, said the new law "is not a model of clarity" and HEW lawyers are studying its "long and complicated" legislative history to determine how to administer it.

Califano also proposed new restrictions that would ban HEW-financed research on prisoners where more than a "minimal risk" was involved.