After losing a fight last year to curtail veterans preferences in federal jobs, a coalition of women's and civil rights groups is trying to persuade the Carter administration to take on the veterans again this year.

"This issue is the number one thing affecting the progress of women in government, in hiring and promotions," said Lynn Revo Cohen, chief lobbyist for the coalition led by Federally Employed Women (FEW).

First, however, the women must convince Carter aides that they will provide a much more potent lobbying effort than they mustered for the cause last time, sources on both sides agree.

As part of his drive to overhaul the civil service system, President Carter had called for cutbacks in the lifelong job preferences extended to 30 million veterans, a group that is 98 percent male and 92 percent white.

Most persuasive to some undecided members of Congress was Carter's argument that the existing provisions pit the older veterans not only against women and blacks, but against younger of disabled veterans, whose needs may be greater.

But, under pressure from well-or-ganized veterans groups, Congress killed the preference cutbacks, making this the only major element missing from Carter's original civil service overhaul package when it won passage last fall.

While some members of Congress indicated they will support the proposals for another go-round if called on, there was also a feeling that, as a congressional aide put it, "there's no real reason to think we'd stand any better chance this year than we did last."

Veterans groups and their supporters on Capitol Hill maintain ardently that they earned their preferences as part of a deal with the government in exchange for their services and that it would be a serious breach of good faith to curtail them in any way.

The federal Veterans Preference Act of 1944 covers virtually all those who served in the military, whether in combat or not, before 1976. (Those in the all-volunteer army are not covered.)

Some observers argue that the issue will dissolve in about 10 years, in any case, as older veterans retire.

With chances murky for a renewed legislative battle on the issue, some advocates of change are looking to the courts as an alternate, albeit slower, springboard for change.

They have seized on a case now before the Supreme Court which, while specifically concerned with the Massachusetts state veterans preference provisions, could have an impact on similar provisions in 46 other states as well as the federal government.

In the case, a former state employe named Helen B. Feeney charged that her attempts to win promotions were repeatedly blocked because of the preferences given to veterans, even though she scored higher on civil service exams.

Last spring, a federal court in Massachusetts ruled that the state preference statute is unconsitituional because it "deprives women of equal protection of the law."

Controversy over the case escalated in December when the Justice Department filed a friend-of-the-court legal brief which angered the president and drew protests from women's groups because it supported the principle of veterans preference rights in a way that seemed to contradict the president's proposals to limit them.

Last week, four federal agencies including the Department of Defense submitted a second brief to the Supreme Court which was, according to one top administration official, "substantially different" in thrust from the first U.S. brief.

The first brief reflects the view of Justice Department lawyers that, if the Supreme Court upholds the ruling in Massachusetts, it could jeopardize a whole range of federal benefits accorded to veterans.

The second brief was filed jointly by the Department of Defense, the Equal Employment Opportunity Commission, the Labor Department and the Office of Personnel Management (OPM). While the Justice Department brief was signed by male attorneys, the second was signed by female attorneys.

With seeming irony, the second brief, representing the views of groups most opposed to veterans preferences, defends the federal preference provisions as much "less severe" then the Massachusetts statutes.

"It attempts to make the point that the Massachusetts law is so different [from the federal law]" that if the court finds the state law unconstitutional, "it certainly will no mean the federal programs are unconstitutional too," said Alan K. Campbell, director of OPM and the president's point man on the veterans preference issue.

"We wanted to make sure it was elear that the federal veterans preference issue is a policy issue not a constitutional issue," he said.

By accepting that some veterans preferences are reasonable and picking their shots, the advocates of change hope to knock out what they see as the most extreme and discriminatory manifestations of the concept.

The Massachusetts law gives veterans absolute preference over nonveterans in hiring and promotions, while the federal law gives veterans an advantage by adding a certain number of points to their civil service scores but still "insures some measure of individual competition," the brief emphasizes.

Under the absolute Massachusetts preference, "Few if any females have ever been considered for the higher positions in the state civil service," the brief quotes the earlier court finding. The court found, for instance, that if an eligibility list for administrative assistants had been compiled without veterans' preference, "nearly 40 percent of the women would have occupied the top third of the list which is now occupied, with one exception [a female veteran] by men."

Under the federal system, by comparison, at least women "are not completely foreclosed from consideration," the brief goes on.

In stressing such distinctions, the second brief is a "much better articulation, from the viewpoint of civil rights and womens' groups, of what is needed to show an intent to discriminate," said Judith Lichtman, executive director of the Women's I egal Defense Fund.

The second brief [like the Justice Department brief] was submitted after the filing deadline in the case and, sources noted, the court could refuse to consider it.

In a separate action last month, Sears, Roebuck & Co. used veterans preference laws as ammunition in an attention-getting counterattack on federal antidiscrimination laws. In a suit against 10 federal agencies, the company charged that government policies of the past had fostered the white male domination of today's work force -- a situation the company says the government now unfairly expects private businesses to change.

The government had, among other things, set ceilings on the numbers of women and blacks (2 percent and 10 percent, respectively) who could join the militany in World War II, thus depriving them of the benefits of the GI bill and federal veterans' preference provisions, Sears charged.

When the Senate defeated the veterans preference cutbacks last year, it left the door open by mandating a congressional study of the subject. The administration, Campbell said, may push for formal hearings this year to lay the groundwork for future legislative action.

The administration has also continued to meet with women's groups to assess their mutual commitment, but some sources on each side say there are still too many issues ahead of this one on the list of competing feminist priorities.

Campbell and others have argued that the preferences should be "refocused", cutting them back for older able-bodied veterans (the majortiy) and maintaining or increasing them for disabled and Vietnam-era veterans.

Male veterans hold half the jobs in the federal government, although they make up only about one-fourth of the nation's total work force; and male veterans hold 65 percent of government supergrade jobs, while women hold 3 percent, government statistics show.

Frustrated federal managers have complained that because of their life-long preference right, older veterans "choke the pipeline" of job applicants, preventing the hiring of younger veterans or nonveterans who may be better qualified.

FEW lobbyist Cohen agreed that last year's loss was a "failure in lobbying" by women's groups. But, she added, "The timing was terrible, right before the fall elections" and most organized women's efforts were diverted to the push for an extension of the Equal Rights Amendment deadline and other business.

This year, the coalition has worked to get its lobbying better organized and to broaden its base of support, she said. "The difference is that now we really are capable of coming up with a big countereffort."

Still, some members of Congress who "stuck their necks out for us may be gun-shy," Cohen conceded. "They got a lot of bad mail and publicity and very little thanks."