A federal judge has ended a landmark lawsuit that for the past 14 years has required the federal government to enforce civil rights laws affecting elementary, secondary and higher education systems throughout the country.

U.S. District Court Judge John H. Pratt, who has presided over the massive suit since it was filed in October 1970 by the NAACP Legal Defense and Educational Fund on behalf of 26 schoolchildren who were attending racially segregated schools and colleges, said in an order made public yesterday that the case could not continue because none of the current plaintiffs has legal standing.

Since his first order in 1973 requiring the Department of Health, Education and Welfare to begin action to cut off federal funds to 10 southern and border states whose public colleges retained vestiges of segregation and setting timetables for HEW's Office for Civil Rights to process compliance reports on public school systems, Pratt had almost singlehandedly battled what he has termed government foot-dragging in the enforcement of civil rights laws.

But in a 31-page opinion, Pratt said that the nature of the case, originally known as Adams v. Richardson and now known as Adams v. Bennett, has changed over the years, from a focus on charges that the Office for Civil Rights was not enforcing the civil rights laws to charges that it was not processing complaints and compliance reports quickly enough.

Pratt said that even though the plaintiffs in the case, who include 50 individuals and 11 organizations, can be injured by discrimination, ending that discrimination cannot be accomplished by the measures they are asking Pratt to take.

He said it was "speculation" to believe that swifter processing would remedy the discriminatory practices, which Pratt said were actually being carried out by the states and school systems and not the federal government.

And using a recent standard set by the Supreme Court, Pratt said that two orders he issued in 1983 "intrude on the functions of the executive branch and violate the doctrine of separation of powers, which is the basic core of standing."

Therefore, Pratt wrote, "It is our holding that all of the plaintiffs . . . lack standing to continue this litigation. Accordingly, we grant defendants' motion to dismiss."

Civil rights groups involved in the case reacted with shock yesterday to the decision.

"It's a tragedy," said June Inuzuka, a staff attorney for the Women's Equity Action League, which joined the suit in 1976. "Without Judge Pratt's orders . . . there is very little we can do in terms of forcing compliance."

Elliott C. Lichtman, a private attorney here who has handled the case since it was filed, said Pratt's decision would be appealed.

He said he believes that the decision is inconsistent with the initial order in the case which was unanimously affirmed by the Court of Appeals.

But Reagan administration officials praised Pratt's ruling.

The decision "recognized" the Department of Education's "independent authority to administer the nation's civil rights laws," general counsel Wendell L. Willkie II said in a prepared statement.

He said the department will "continue thoroughly to investigate alleged violations of these laws."

"After 17 years, the department welcomes this opportunity to resume full responsibility for the day-to-day affairs of the Office for Civil Rights," Willkie said.

The office became part of the Department of Education when the department was broken off from HEW in 1979.

But civil rights groups said that without the continuing pressure of Pratt's orders, the Office for Civil Rights and the Department of Labor's Office of Federal Contract Compliance Programs -- which has authority to enforce some of the laws -- will become less aggressive in requiring compliance.

Rep. Ted Weiss (D-N.Y.), who chairs the human resources subcommittee of the House Government Operations Committe, said that "the suit has been extremely important in getting the states and the institutions of higher learning to focus on the lack of progress toward integration.

"I think the pressure was obviously needed," Weiss said.

"It would be unfortunate if the pressure were now removed," Weiss added, because even with it the Department of Education has been "derelict" and in some instances the states have "gone backward" in their desegration efforts.

The 10 states originally covered by Pratt's order on college desegregation plans were Arkansas, Florida, Georgia, Louisiana, Maryland, Mississippi, North Carolina, Oklahoma, Pennsylvania and Virginia. HEW was also ordered to take action on compliance in 200 local school districts.

The case was later broadened to cover school systems in all 50 states and discrimination against blacks and other minorities, women and the handicapped.

Among the groups involved in the case were the Mexican American Legal Defense and Education Fund, the National Organization for Women and the National Federation of the Blind.

Virginia Education Secretary Donald Finley said yesterday the lawsuit dismissal "isn't really going to change our plans" because the state has been working to increase black enrollment and hiring anyway.

"We have said consistently that we are concerned about the problems that brought about the suit in the first place, and we are going to continue our endeavors to enroll more black students and hire more black faculty and staff regardless of what the federal government does or does not do," Finley said.

Stephen J. Wright, former president of Fisk University and a member of Virginia's State Council of Higher Education, said he believes Virginia will move ahead in achieving desegregation, but that the lawsuit's dismissal may discourage blacks with legitimate grievances from seeking redress under federal civil rights law.

Staff writer D'Vera Cohn contributed to this report.