ALBANY — Gov. David Paterson, already wrestling with a potential $8 billion budget deficit next year, said today he plans to meet with union leaders later this month and has not ruled out layoffs of state workers as a potential cost-cutting measure.

But on a day when prices on the stock market, which has been a key part of New York’s tax revenues for decades, again plummeted, a spokesman for the state’s largest public-employee union said Paterson promised this summer that there would be no layoffs.

“We’re going to talk about the deep fiscal crisis and how we can work together to solve it,” Paterson said today of the session with union leaders, planned for Oct. 21.

He added in a radio interview today that he’s not planning any tax hikes or layoffs of state workers to help get New York out of its fiscal crisis.

But he added on Talk-1300 in Albany that, “I’m not ruling out anything because I don’t know what the future holds.”

That statement conflicts with a promise made to the head of the largest state-employees’ union this summer, according to a spokesman for the union, the Civil Service Employees Association.

“The governor personally indicated personally Danny Donohue over the summer that there would be no state layoffs,” said the spokesman, Steve Madarasz, referring to union President Donohue. “We will hold him to his word.”

But Paterson press secretary Errol Cockfield said that the state’s financial problems have worsened since then.

“Since last summer, when the governor raised early alarms about the state’s budget situation, there has been widespread recognition from our partners inside and outside of government that New York’s fiscal situation has worsened,” he said.

Paterson has been sounding the alarm that the state’s finances are out of whack because of the general economic downturn and more particularly because of the Wall Street meltdown. Bonuses to big producers at investment banks and other securities industries helped to propel state tax revenues far above forecasts in recent years. But next year promises to be far different because of the demise of several big Wall Street firms and the continued struggles of most of the rest.

He has summoned the Legislature back to the Capitol on Nov. 18 to look at cutting $2 billion to balance this year’s budget and said he plans to introduce his proposal for next year Dec. 16, more than a month ahead of the normal schedule.

Paterson did deliver some good news today as well: a deal has been struck between the state and a subsidiary of Advanced Microsystems to build a $4.6 billion computer chip-fabrication plant in Saratoga County. Construction is to start next year and take about three years.

The deal, which includes a $1.2 billion payment from taxpayers and will create 1,465 jobs, “can be in many respects a hub for investment all over the capital region and even a shot in the arm for the whole upstate economy,” Paterson said.

But that won’t help the state’s immediate budget woes.

An analyst for a conservative think tank thinks that conflicts between employers and public-employee unions are inevitable as the state tries to deals with a financial downturn that he says is the most serious the state has experienced in decades.

“There is going to need to be confrontations with public-sector unions,” said the analyst, E.J. McMahon of the Manhattan Institute’s Empire Center. He said that’s true both at the state level and probably in school districts.

That’s because school aid, on which the state is spending $21 billion this year and is slated to spend more than $23 billion next year, “is the 800-pound gorilla in the room,” he said. And cutting school aid from the state will mean that school boards will have to figure out a way to save on their big cost drivers: teacher salaries and benefits, McMahon added.

But even though Paterson for the moment has ruled out tax hikes, others say that’s the only fair way to go.

“When push comes to shove and we’re in tough times, there really has to be shared sacrifice,” said Dan Cantor, executive director of the Working Families Party, a union-backed political group.