The state could owe an estimated $90 million in back pay to public employees who were paid different wages for the same jobs, according to an appeals-court decision yesterday.

Judge David Armstrong reversed a lower-court decision in a class-action lawsuit that involves more than 4,000 employees who have worked for the state since 1996. In the suit, the employees challenged the state's wage system for higher-education and general-government workers in similar jobs.

The state Attorney General's Office is "carefully considering" the appellate court's ruling and deciding whether to petition the state Supreme Court for review, said Spencer Daniels, assistant attorney general.

The Governor's Office declined to comment because the case remains active.

If the decision stands, Daniels said the state could owe employees $10 million to $11 million a year back to 1996, or about $90 million on the low end. The attorney for the employees, Martin Garfinkel, estimated the annual figure was $11 million, which would make the total $99 million. If the state were ordered to pay $90 million, it would average out to about $22,500 per employee.

"It is about equal pay for equal work for state workers," said Garfinkel, the attorney for the Seattle law firm of Schroeter Goldmark & Bender, which represented the employees.

Two custodial workers at Western State Hospital and a medical transcriptionist at Eastern State Hospital filed the class-action lawsuit in October 1999. The suit, which was consolidated with a separate lawsuit filed by the Washington Public Employees Association, sought back pay and changes to the wage system.

At the time, an electrician who worked in general government made less than an electrician who worked in higher education. A hospital dietitian was paid more than a dietician in a college, according to the suit.

The employees and the state agreed to settle the suit in 2001, and the state promised to equalize wages over three years in 172 job classifications. The parties estimated then that it would cost the state $11 million to reconcile the wage inequities in the first year, according to attorneys on both sides.

That settlement fell apart when the state Legislature did not approve funding. In 2003, Thurston County Superior Court Judge Daniel Berschauer ruled in the state's favor. Judge Armstrong, in the Court of Appeals Division II, reversed the decision yesterday and sent the case back to Berschauer.

If the state does not petition the Supreme Court to consider the case, the state could owe back pay to state employees who worked similar jobs for different wages depending on whether they worked in higher education or general government.

Those affected by the decision worked in a wide range of professions, including architects, paralegals, farmworkers, photographers, carpenters and administrative assistants. It could also alter employee pensions and benefits.

In yesterday's decision, Armstrong wrote, "no rational basis exists to set different base salary schedules for state workers doing essentially the same work." Therefore, he wrote, the state had denied employees equal protection.

At the Attorney General's Office, Daniels said, "Obviously, we're disappointed. We're also somewhat perplexed by the analysis of the court on the equal-protection claim."

The state argued that the higher-education employees and general-government employees belonged to separate classes.

"In our view, the question is whether there was anything improper with the fact that you had two separate systems, in turn leading to different pay for some of the people who did the different work."

The court ruled that all the employees who were paid less than their counterparts were part of a single class.

Sharon Pian Chan: 206-464-2958 or schan@seattletimes.com