Yvonne Bechet is a black policewoman who finally got her sergeant's stripes in December, due in part to a racial quota system that is expected to reshape the command structure of the New Orleans police department dramatically.

Larry Lombas is a white officer, still waiting to make sergeant. He says he believes the quota--one black promoted for every white until the supervisory ranks are 50 percent black--has cut his chances for advancement in half.

"They say somebody has to suffer," Lombas said. "Well, why do I have to suffer? I never hurt anyone. I just did my job. I always worked closely with blacks. But now they're taking something from me that I worked for."

"Nothing has been taken from them that was rightfully theirs," said Bechet. "Half their opportunity belonged to me."

Bechet and Lombas are on opposite sides of one of the country's most important civil rights cases, one lawyers say could radically alter the nation's approach to remedying employment discrimination.

In January the Reagan administration intervened in the case, joining in the challenge to the quota system, and transforming the case into a crucial confrontation in the legal war between the Civil Rights Division of the Justice Department and the nation's civil rights lawyers, represented in New Orleans by the NAACP Legal Defense and Education Fund Inc.

At stake is the most effective remedy for discrimination blacks have found: comprehensive quotas, like those applied in the police departments in Birmingham and Detroit and now in New Orleans, that bring about rapid change in hiring and promotion.

Before the New Orleans plan took effect in December, blacks held only seven supervisory posts (five sergeants, two lieutenants) out of 283 in the police department of a city 55 percent black. Combined with another part of the settlement agreement, the creation of 44 supervisory slots exclusively for blacks, the supervisory ranks will become 50 percent black.

Blacks benefit from such quotas regardless of whether, as individuals, they were specifically denied a promotion or a job on racial grounds.

The Reagan administration hopes this case ends that situation. The Civil Rights Division has told the Fifth U.S. Circuit Court of Appeals that the practice violates both civil rights law and the Constitution.

"Persons who have not been victimized by the employer's discriminatory practices," the government's brief said, have no claim to special treatment under quotas. The practice is an "inequitable infringement on the rights of innocent non-black officers."

If the administration view prevails, said Barry Goldstein, of the NAACP Legal Defense Fund, "The Equal Employment Opportunities Commission may as well fold up shop and go home. That's not hyperbole. There will be no effective remedy against the worst offenders in the worst situations."

The quotas in the New Orleans police department were imposed as part of a wide-ranging consent decree the city accepted in 1981 to settle a discrimination suit brought by black officers in 1973.

However, a U.S. District Court judge invalidated the quotas as excessively harsh on non-minorities in the department. A Fifth Circuit panel voted 2 to 1 to reinstate the disputed percentages. And, on Feb. 14, at the urging of the Justice Department, the full circuit court agreed to review the panel's decision.

"The worst situation" was exactly what New Orleans was, in the view of blacks who initiated the discrimination complaint against the police department. Before 1950, no blacks were hired by the police department. When the suit was first filed in 1973, in a city then 45 percent black, only 6 percent of the department was black. The department of 1,400 is now 20 percent black.

Black police officers hired in the 1960s and 1970s say discrimination was part of the daily routine, from assignments (they were confined to all-black neighborhoods and kept off elite plain-clothes and tactical units) to bathrooms. As late as 1970, according to court affidavits, some station houses had segregated bathrooms, the blacks sharing with prisoners.

Blacks were able to pass examinations leading to promotion, but they were ranked low on the eligibility lists in part because seniority in the department counted for 40 percent of the ranking. Often the department would allow a list to expire just before reaching the highest ranking black on it.

In 1973, for example, nine of 44 blacks competing for promotion to sergeant made the list. But only one of 80 promotions went to blacks that year. Before the imposition of the quota system, only 20 blacks in the history of the department had made it above the lowest rank.

Lawrence Preston Williams, one of the blacks who sued in 1973 and then left the department to become a lawyer, remembers his first months as a New Orleans police officer in 1968. Rather than having a permanent partner like other officers, he was assigned a different one each day.

"I was told by my lieutenant that the white officers felt everyone should bear the burden of riding with the black," he said.

Bechet said that the day she first reported for duty in a district 14 years ago the entire platoon called in sick in protest.

In addition to being unjust, the department's treatment of blacks caused the quality of police work to suffer, Williams said. "As hard as they tried, the white police couldn't get information from blacks," Williams said.

On the street, police who couldn't or wouldn't distinguish among blacks stopped blacks indiscriminately. "There were unnecessary confrontations, even with the most well-intentioned whites," Williams said.

In 1981, the Justice Department reported that it had received more brutality complaints about New Orleans than from any other city in the United States. In that same year, New Orleans police officers shot nine blacks in incidents critics charged involved excessive use of force. The city paid more than $1 million that year to settle abuse charges brought by blacks.

Finally, in November, 1981, police hunting the killer of a white patrolman swept through a housing project, killing four blacks in pre-dawn raids and injuring a dozen others. Three officers were convicted March 28 of this year of violating the civil rights of a black man brutally interrogated during the hunt.

The discrimination suit filed by Williams and 12 other black officers was dormant until 1980. The day it was scheduled to go to trial, the city agreed to the consent decree that required affirmative action in hiring and training of black police officers, the creation of 44 new positions above the officer level for blacks and the disputed promotion quota system.

Angry whites and some of their lawyers say Mayor Dutch Morial, the city's first black mayor, settled the case to get black votes in his bid for reelection. Morial said in an interview that the city settled because "it was in trouble" in the suit.

In addition, he said, "It is consistent with the philosophy of this administration to bring about a police department that is reflective and representative of the totality of this community." Morial said that as the proportion of blacks in the department has increased the quality of the city's policing has also improved.

Nearly three-fourths of the officers in the department signed petitions protesting the agreement. A group of white and Hispanic officers hired their own lawyers and were allowed to intervene in the case in protest.

"We felt our careers were over," said Lombas, who has tried for promotions three times during his 15 years on the force. "If this thing is finalized, you're going to see a mass exodus of whites from the department."

"How far can you go in infringing the legitimate legal rights of non-black employes in order to vindicate the rights of blacks in general who were not themselves victims?" asked Lombas' lawyer, Sidney M. Bach. "It's not that you don't have remedies for discrimination . It's a question of what remedies.

"Now you have the irony of the federal law against discrimination being violated in the name of upholding it. Whites, women and Hispanics are being discriminated against on account of their race" in New Orleans, he said.

"What would I say to white officers if we were sitting around discussing this over a beer?" asked Williams, the ex-officer who brought the suit. "I'd say 'that's tough.' "