Six Maryland legislators were handed last night one of the most important and intractable tasks of the 1978 legislative session: working out a compromise on the almost uncompromisable issue of public funds for abortions.

Inextricably bound up with this issue - and thus bound up with this group's deliberations - is the state's $4.35 billion budget for next year, which the House and Senate must approve before the session can end.

But the budget cannot be passed by both houses until the committee induces the sharply divided chambers to agree on the exact language that will be used in determining under what circumstances state funds will be used to pay for inidgent women's abortions.

The persistent disagreement between the two chambers will make the group's task extremely delicate, since the compromises they must reach involve subtle semantic nuances. If, at a key point in the abortion-funding amendment, the committee substitutes the word "emotional" for the word "physical," hundreds of women who might have been barred from receiving Medicaid funds will be eligible for state-funded abortions.

"The question," Senate President Steny H. Hoyer explained yesterday, "is under what circumstances will the money ($1.6 million in state funds) be expended for abortions for poor women."

Hoyer added that it is almost certain that some new restrictions will be placed on the use of public money for abortions, since the House has twice flatly rejected the option of unrestricted abortion funding.

The Senate, however, has made it clear that it finds the House-approved restrictions on abortion funds far too severe. The House has twice voted to allow abortion funding only if the pregnancy endangers the life of the mother, if the pregnancy resulted from rape or incest, or if two doctors determine that continuation of a pregnancy would cause "severe and long-lasting health damage" to the mother.

"It is obvious," Hoyer said yesterday, "that if the committee is going to reach a middle ground it will be . . . (to find) some language that is less restrictive than the House's."

House Speaker John Hanson Briscoe added that "there will probably be some liberalization . . . (the committee will find some more ways that an abortion could be provided to a poor woman."

But the question of how a compremise on this controversial, emotional issue will evolve depends entirely upon which the legislators - three delegates and three senators - are appointed to the conference committee. And the job of making the appointments fell to the two legislative leaders: Hoyer and Briscoe.

For Hoyer, the choices were easily narrowed: since the conference committee is appointed to deal with budgetary questions, his three choices would come from the Senate Budget and Taxation Committee that had dealt most closely with the budget.

Furthermore, since the 47-member Senate had vote 27 to 20 for unrestricted abortion funding, it would make sense to pick two legislators who supported this position, and one member of the opposing faction.

Briscoe, too, could narrow down his choices, using a similar logic: the three delegates he would put on the conference committee would have to be members of the House Apprepriations Committee; two would probably have to have been in favor of restrictive funding and one against.

Then, there was one more key reality both leaders had to deal with: the legislators who had been strong advocates on one side or the other of the emotional issue would probably be the ones who would find it hardest to compromise.

"I wouldn't put a Leo Green (an ardently antiabortion delegate) on there and I wouldn't put a woman on there," said Briscoe, ". . . because you want people who can work out a compromise." Briscoe added that most of the eligible women delegates had been closely identified with one position or another on this question.

In addition to working through the decision of who will sit on the conference committee, Briscoe and Hoyer said yesterday that they had been at work preparing an agenda of possible abortion funding compromises for the committee to consider.

Among the points the two men mentioned were broadening the restrictions to allow abortions for women carrying a fetus that can be shown to be deformed; allowing abortions for women whose psychological health would be affected by the pregnancy; and softening a House-approved requirement that women victims of rape or incest must report the violation to law enforcement authorities before being eligible for Medicaid abortion funds.