WASHINGTON (AP) _ When Billie Walls, a black student at the University of Maryland, applied to medical schools this fall, she shied away from ones that did not seem welcome environments for minorities.

``I didn't even apply to schools that weren't minority-friendly,'' Walls said. ``Medical school is hard enough. You need to find a place where you feel comfortable.''

More minority students may be steering away from medical schools, particularly in states affected by affirmative-action rollbacks, according to a study released Saturday by the Association of American Medical Colleges.

The association's study of the nation's 125 accredited medical schools shows an 11 percent drop in blacks, American Indians, Mexican-Americans and Puerto Ricans applying to medical schools. In addition, 6.8 percent fewer of those minority students were accepted for 1997 than in 1996.

Some educators fear the figures show that actions of a federal court in Texas and the voters of California to end educational preferences for minorities are echoing through the nation. Minorities are discouraged from applying, and administrators have become overly cautious about admissions policies, they contend.

``This is an ominous sign for the medical community and our nation, which badly needs a physician work force that is both diverse and reflective of our society as a whole,'' said Jordan J. Cohen, president of the medical school association.

He said the downturn is clearly linked to Proposition 209, with which California's electorate ended affirmative action in state institutions, and the federal court decision in Texas. Together, they ended affirmative action in four states.

According to the report, 17 percent fewer minority students applied to their state medical schools in California and in Texas, Mississippi and Louisiana _ states covered by the 5th U.S. Circuit Court of Appeals decision that affirmative action is unconstitutional. The number accepted in the four states dropped by 27 percent.

``The threat to affirmative action in many states is sending the signal to minority students that they are unwelcome,'' said Hector Garza, vice president for access and equity programs at the American Council on Education.

The council conducts its own annual status report on minorities in higher education, which showed slight progress in minority matriculation until 1995-96.

``Just as we were beginning to see some upward mobility at all levels of the educational pipeline, we see this backlash to affirmative action having an adverse effect,'' Garza said.

One group that studies problems involving racial preferences, the American Civil Rights Institute, cautioned against attributing national fluctuations to the two California and Texas events.

But educators at institutions outside those states said they have witnessed the impact of the rollbacks firsthand.

Dr. R. Allen-Noble of the Medical College of Georgia said the school's minority enrollment has dropped since it revoked scholarships for minorities in 1996, when the state's former attorney general declared the scholarships illegal in light of the Texas court decision.

``Institutions are so afraid of a lawsuit that they are being overly cautious,'' she said.