The Fairfax County Human Rights Commission, in its largest negotiated settlement of discrimination charges, said yesterday that a Reston engineering supply firm has agreed to pay $35,000 to a former employee who charged she had been sexually harassed and discriminated against on the basis of sex.

Hunter Associates Laboratory agreed to the payment without admitting any of the charges that Hildie Carney filed with the agency more than a year ago were true, the commission said.

Carney, a marketing coordinator, had charged the company denied her a promotion because of her sex and that she was fired for insubordination when she refused to perform perfunctory secretarial duties. Carney also had charged that during her six years with the company, a supervisor made continuous attempts to fondle her and had propositioned her.

Hunter officials denied both charges and said the agreement was based on expediency rather than validity.

"We agreed to this settlement because we feel it is in the best interest of the company to avoid the time and expense of litigation," William Donnelly, a lawyer for the company, said. "Complex litigation of this nature would be unduly disruptive to the company's business."

Carney, 47, a Fairfax City mother of four, was barred by terms of the settlement from commenting, but parties familiar with the case said she had complained to management that she was repeatedly approached by her supervisor. Frequently, the parties said, the supervisor would try to kiss Carney and proposition her in front of both customers and employes. She requested that she no longer be asked to travel or work with the supervisor, who was not named in the settlement.

Finally, the parties said, when repeated attempts to fend off the supervisor failed, Carney was transferred to another department. A position opened up in that department, but Carney contended she was told by company officials they wanted to hire a male. After a man was hired to fill the position, Carney was dismissed when she refused to perform secretarial tasks.

Fairfax Human Rights director Patricia Horton called the settlement a victory for local discrimination agencies and women who cannot afford to hire a private attorney to prosecute sexual complaints. Most of the Fairfax agency's sexual harrassment settlements have been for about $3,000 each, she said.

"This settlement represents the growing realization by both victims and employers in the workplace that sexual harassment is, indeed, a very important problem and that the only way this problem can be successfully addressed is if victims like Carney have the courage to bring these complaints to the attention of investigative agencies . . . and if employers like Hunter Lab are willing to give credibility to these complaints and take appropriate remedial action," Horton said.

"This is a victory not so much for Hildie Carney or Hunter Labs but for the many silent victims of sexual harassment."

Donnelly said the man accused of harassing Carney is no longer an employee of the company but works as a consultant for the firm.