In the first display of progress in the long dispute over federal payment for abortions. House-Senate conferees reached tentative agreement on a rape-and-incest provision yesterday, but deadlocked on other provisions and will meet today.

The $60.1 billion funding bill for the Departments of Labor and Health, Education and Welfare has been held up by the abortion dispute. House Appropriation Committee Chairman George H. Mahon (D-Tex) pleaded with conferees to reached some agreement before Congress adjourns.

The conferees had their most amicable give-and-take session so far after months of harsh talk, and it appeared at one time that significant senate concessions to the House's rigid anti-abortion position would be adopted. But there was no agreement before the conference broke for the evening.

The conferees have long agreed that where pregnancy is a direct threat to the life of the mother, abortion should be allowed. The conference has foundered over a Senate provision that Medicaid abortions also be allowed where the pregnancy would harm the physical health of the mother, even if it wasn't life-threatening. Senators made a substabtial retreat on this provision yesterday but the House still balked.

Senators had previously insisted that any such mental or physical health danger to the women or fetus be grounds for Medicaid abortions. But yesterday Sens. Warren G. Magnuson (D-Wash) and Edward W. Brooke (R-Mass.) agreed to limit this provision to "serious ohysical health damage" to the mother, dropping both mental health danger and fetal damage. This was the most far-reaching concession offered yet in the conference. But when Rep. David Obey (D-Wis: proposed accepting it with the formulation "grave physical health damage," his House colleagues turned him down 6 to 6.

The tentative agreement on rape anf incest yesterday would allow federal funding of "prompt treatment of the victim of rape or incest" The House dropped its requirement that the treatment take place before the fact of pregnancy was known and had been reported to a law enforcement officer.

Equally important, it dropped a requirement that only "forced rape" cases would be eligible for such treatment. The significance of simply using the word "rape" instead of "force rape" is that it appears to allow "treatment" of cases of statutory rape, and this would allow aid to any girl under the age of consent (usually 18) who became pregnant. Most jurisdiction define statutory rape as sexual intercourse with a minor even if she gives consent.

According to one opponent of the ban on Medicaid abortions, about a third of all abortions are performed on minors. If the same proporttion holds among Medicaid patients, then about one third of the 251,000 annual abortions performed under Medicaid before anti-abortion language was inserted last year could still be performed - since the pregnancy of a minor is automatically deemed statutory rape.