A curious thing is happening to working women on the road to equality. They're getting less of it.

That, at least, is the consensus of most of the witnesses who testified yesterday before the Equal Employment Opportunity Commission on job and wage discrimination in the workplace.

Despite all the publicity on sex bias, despite all of the protest movements and other events in recent years aimed at improving their lot, working women continue to receive the lowest pay, the worst assignments and the more demeaning forms of workplace harassment, witnesses said.

So frustrating is the situation that Catherine East, speaking on behalf of the National Organization for Women Legal Defense and Education Fund, facetiously suggested that a truly "separate but equal" arrangement might be preferable to present conditions.

"I don't object so much to the segregation as I do to the fact that it often results in lower pay and status for women," she said.

Terry Odendahl, a research associate for the Washington-based Business and Professional Women's Foundation, said public attitudes and policy "have not kept pace" with the rapidly increasing participation of women in the workforce.

More than 49 percent of all mothers with children under 18 and nearly 41 percent of all mothers with children under six, are working, Odendahl said. There are 7.7 million single-parent families headed by women, she said.

Yet, said Odendahl, working women continue to be treated as if they and their jobs were secondary -- even though their wages most often are used, in whole or in substantial part, to finance family operations.

"Since the image of women as dependent on a father or husband persists, public policy does not deem unequal pay and opportunity for women a major concern," Odendahl said.

Full-time women workers earned 64 cents for every dollar earned by men in 1955, according to Odendahl, who based her figures on Census Bureau research. But she said the most recent census data (1978 figures) show women earning an average of 59 cents to every dollar paid men.

A. H. Abshire, personnel director for the City and County of Denver, offered some disagreement.

After acknowledging that his city has been the target of a major sex discrimination suit, Abshire said: "Concentration of women in certain occupations and a spread in income between men and women can be explained on economic grounds, and is not proof of discrimination."