The House, yeilding a bit of ground to the Senate yesterday, voted 263 to 142 to slightly loosen its prohibition against free federal abortions for low-income women.

The Senate, which favors a more permissive stance on federal funding of abortions, promptly rejected the proffered House compromise and endorsed a counterproposal.

Though the basic difference over federal funding of abortions remained unresolved last night, the Senate feeling heat from federal workers who may face "payless paydays" soon if the abortion dispute continues to hold up basic funding for several major agencies, approved an emergency "continuing resolution" that would provide funds for those agencies until Oct. 31. That would give the House and Senate two more weeks to battle over the basic abortion issue.

The continuing resolution contains a curb on abortion, but only until Oct. 31. Whether the House will approve it was uncertain last night. Senators said they believe it is the first time in living memory that the Senate has initiated an appropriations bill, which is the prerogative of the House.

The conflicts has held up final action on the $60.1 billion funding bill for the Labor and Health. Education and Welfare departments despite the fact that the new fiscal year started Oct. 1.

The House, in a series of votes earlier this year, voted to cut off all U.S. funds for about 261,000 abortions performed annually under the Medicaid program - except when the abortion was needed to save the life of the mother.

Yesterday, the House offered to add another exception to the general cutoff: federal funds could be used for "medical procedures, performed before the fact of pregnancy is established, necessary for the prompt treatment of the victims of forced rape or incest reported to a law enforcement agency." This provision means that if a woman reported rape or incest to the police, she would be eligible for a dilation and curettage or "morning-after" pill, so long as the treatment was administered with a few days or weeks at most, and it wasn't established that she was actually pregnant.

Although medical experts have estimated that only a few thousand women a year would be eligible for treatment under either the "life of the moter" or "rape and incest" provisions, some House members said the new "rape and incest language was a potential loophole that shouldn't be added. They wanted to stand pat on the "life of the mother" exemption only Rep. Henry J. Hyde (R-Ill.), original sponsor of the abortion ban, declared that he preferred not to add the new language. However, an attempt to beat the addition of the language failed, 209 to 206.

A few moments after the House vote, the Senate Appropriations Commettee met and acting Chairman Warren G. Magnuson (D-Wash.) announced that he planned to move on the floor to reject the House language and offer a substitute that also would allow federal funding of abortions "if the woman or fetus would suffer serious health damage" if the pregnancy continued. Foes of abortion say this is far too broad and would allow doctors to prescribe abortions in a large number of cases forbidden by the House bill. The full Senate subsequently endorsed this counter-proposal by voice vote.