The Reagan administration plans to endorse a disputed amendment prohibiting federal Family Planning Program funds for any group advising pregnant women of their legal right to abortion, telling them where to obtain one or performing abortions, officials said yesterday. Exceptions would be made only in cases where continued pregnancy threatens a woman's life.

Sponsored by Rep. Jack Kemp (R-N.Y.) and Sen. Orrin L. Hatch (R-Utah), the amendment would have a double-barreled impact.

Under the existing program, no government funds may be used to perform or encourage abortions, but women must be told of their legal right to terminate pregnancy and be given a list of places where they could obtain abortions.

The amendment would bar such counseling and referral in FPP-funded clinics and hospitals.

The proposal also says that if a group, at some separate site, uses nonfederal funds to advise women on abortion or perform abortions, it cannot participate in the program.

Thus, groups such as Planned Parenthood, which rely on their own funds to perform abortions, would have to drop out of the FPP or cease nonfederally funded abortions and abortion counseling.

The administration has not backed major legislative changes along such lines, but Jo Ann Gasper, deputy assistant secretary of the Health and Human Services Department for population affairs, said yesterday, "We do support the Kemp-Hatch amendment." Notification to Congress is being drafted.

Hatch contended recently that the amendment returns the program to what he said has always been its basic purpose: advising women on preventing pregnancy rather than terminating it. Passage of the amendment would end an "outrageous distortion of the intent of Congress," he said.

Although the General Accounting Office has found "no evidence that [FPP] funds have been used for abortions or to advise clients to have abortions," a spokesman for the American Life League, a vigorous supporter of the amendment, said, "We feel in practice they [the clinics] encourage abortion."

Kemp plans to offer the amendment next week when the House Appropriations Committee takes up an emergency fiscal 1986 funding bill for programs including the $142.5 million FPP. Its regular funding and reauthorization, which technically expired Sept. 30, was blocked by a dispute over similar provisions.

The amendment is expected to face strong opposition from Rep. Henry A. Waxman (D-Calif.) and Sens. Lowell P. Weicker Jr. (R-Conn.) and Howard M. Metzenbaum (D-Ohio), among others.

Metzenbaum yesterday threatened a filibuster against the proposal. Some family-planning groups have said they can raise enough votes to block the amendment in the House or Senate but expressed concern that a parliamentary snarl would jeopardize funding.

Gasper said the administration also favors notifying parents when a teen-age girl is given contraceptives. In 1983, the courts struck down an HHS attempt to do so.

The FPP, created in 1970, is designed to provide women with birth control and fertility information and has always been forbidden to fund abortions.

At issue now is a program guideline drafted in the late 1970s, but in general practice since the early 1970s.

It says, "Those requesting information on options for the management of unintended pregnancies are to be given non-directive counseling on the following: prenatal care and delivery; infant care, foster care or adoption; pregnancy termination."

Scott Swirling, director of the National Family Planning Association, said adoption of the anti-counseling and referral language could destroy the "entire Family Planning Program . . . . Not a single participating organization could ethically stay in the program because it would mean breaching medical ethics by concealing from pregnant women a legal medical option."

Faye Wattleton, president of the nonprofit Planned Parenthood Federation of America, which operates more than 700 family-planning clinics and receives about $30 million annually from the program, said the amendment is "patently unconstitutional."

About 56 percent of FPP funding goes to state and local health departments and hospitals. Planned Parenthood gets 22 percent.