State Senate President Melvin A. Steinberg today proposed convening a special session of the General Assembly to aid 10,000 long-term unemployed workers whose benefits were cut off last week. But Gov. Harry Hughes, who would have to call the session, indicated such an action is unlikely.

The beneficiaries of Steinberg's plan would be persons who first faced the loss of benefits in August 1982, but who won an extension at a special one-day legislative session. Those additional benefits were tied to the state's unemployment rate, which has since dropped from close to 8 percent to the current 6.2 percent. Under a complicated formula, the extra benefits "triggered-off" because of the improvement in the economy as reflected in the lower unemployment rate.

Steinberg, who would like to see a special session called before Thanksgiving, said he expects to have details of a bill worked out by next week. "I want business, labor, members of the legislature and the governor to favor the plan before I go forward with it. But I think this is a very serious problem and we need to react to it."

Steinberg's idea is to localize the way unemployment levels are calculated. Then, instead of using the statewide unemployment level, the cut-off would be tied to the rate at each of the state's unemployment centers. Such a plan, for example, would likely make unemployed workers in Baltimore City eligible for benefits longer than those in the Washington suburbs.

The governor said he would "look at anything he puts in front of me, but I have some problems with what I understand of the concept. That means that an individual who doesn't live in one of those areas would be left out. In other words, some Marylanders would be receiving benefits that others wouldn't, even though their unemployment needs might be just as great."

Hughes met with Steinberg and House of Delegates Speaker Benjamin L. Cardin today, but all three men said talk of a special session was limited to brief comments as the legislators were leaving the governor's office.

Cardin said that if all sides could reach agreement on the issue he would not oppose the idea of a special session, "but we have to be careful with this. We don't want to raise false hopes."

Christopher Costello of the state Chamber of Commerce and Thomas Bradley of the AFL-CIO already have met briefly on the subject of a special session. Steinberg conceded business leaders would have to be given some incentive to support a bill that could only cost them money by continuing benefits of up to $161 a week for 10,000 people.

"Obviously anything that is going to mean additional benefits is not going to be pleasing to them on the face of it," Steinberg said. "But I'm not asking to add people to the program, I'm simply asking to return people who were removed by a statistical quirk."

Steinberg calls his proposal Designated Area Benefits--DAB--and said it would expire next June as had been planned when the original legislation passed last year.