Supreme Court nominee David H. Souter said yesterday he would clarify his views on abortion "to the extent it is constitutionally appropriate" when he goes before the Senate Judiciary Committee in September.

As antiabortion groups expressed different degrees of concern about the New Hampshire jurist's fragmentary record on the sensitive issue, Souter continued to make his courtesy calls on the senators who will vote on him as a successor to retiring Justice William J. Brennan Jr.

The longest session -- lasting more than an hour -- was with Judiciary Committee Chairman Joseph R. Biden Jr. (D-Del.). Biden declined to characterize his reaction, saying, "It was a private discussion, and we'll keep it that way."

Another Judiciary Committee member, Sen. Patrick J. Leahy (D-Vt.), said he told Souter he should expect questions on abortion "from both sides." Asked if he thought Souter would be forthcoming, Leahy said, "I hope he will be, but I think he's still sorting out in his mind how far he should go."

Leahy said the judge told him he had been asked no "litmus test" questions by President Bush or other administration officials before the appointment was offered him.

The former New Hampshire Supreme Court justice had just begun serving as a federal appeals court judge when President Bush tabbed him for the Supreme Court. When reporters in Biden's office inquired about his reaction to all the speculation about his abortion views, he said, "I think I look forward to making the position clear to the extent it is constitutionally appropriate when I get to the hearing."

Asked later about the letter he wrote in 1981 for the New Hampshire Superior Court bench, opposing any discretionary role for judges in cases where minors seek abortions, Souter said, "I think you should save any issue of that sort for the confirmation hearings, where I'm sure that issue will be addressed."

The letter was cited by officials of one antiabortion group, the American Life Lobby Inc., as "just one more troubling aspect" of Souter's record, which also includes service on the boards of two hospitals that permitted abortions to be performed.

Concord Hospital President Richard Warner said Souter participated in a vote of the hospital's board in February 1973, a month after the Roe v. Wade decision, to allow doctors to perform abortions there. He said minutes of the meeting reflect no dissent or other discussion from Souter or other board members.

But the National Right to Life Committee said Souter's 1981 letter "reveals nothing" of his views on the legality of abortion and his role in the "pro-abortion policies" of Concord and Dartmouth hospitals "remains unclear."

While the American Life Lobby called on its members to demand that Souter answer questions about his abortion views, a third antiabortion group, Concerned Women for America, said in a statement, "It would be improper for Judge Souter's hearings to deteriorate into an abortion inquisition. . . . No matter what his personal beliefs on abortion may be, Judge Souter is qualified to sit on the high court if he is a strict constructionist, has the necessary experience and education, and is morally upright."

One of the Senate's leading abortion-rights advocates, Sen. Bob Packwood (R-Ore.), told reporters yesterday he thought "about three-fourths of the Senate" would rather not have Souter spell out his views on abortion, so the nomination does not become "fiercely contested."

Packwood, who is not on the panel, said he thought the Judiciary Committee should ask Souter about his abortion position, but added that whether the nominee gives a clear answer should not strongly affect his nomination.

Evidence that Packwood might be right came from the reaction of Leahy, who opposed President Reagan's nomination of Robert H. Bork to the Supreme Court. Leahy said he found Souter "not at all like Bork" in temperament, calling him "quiet, pleasant and obviously intelligent." Leahy recounted with obvious delight an example of Souter's humor.

"When I told him I expected to spend much of the August recess reading his opinions," Leahy said, "he responded, 'You'll have no trouble sleeping.' "