Morris Abram, one of President Reagan's three nominees to the U.S. Commission on Civil Rights, has informed the White House that he will not accept appointment unless one of the two other nominees also is confirmed, according to White House and congressional sources.

The sources say Abram objects to a compromise proposed by Sen. Arlen Specter (R-Pa.) that would put a seven-year limit on commission memberships. Under this plan, only one commissioner, Rabbi Murray Saltzman, would be replaced, with Abram his likely successor.

Saltzman is the only Jew on the commission. According to a Senate official, Abram, who also is Jewish, thinks that Specter's plan "boils down to a quota--one Jew for another--and he told them he won't have any of it."

The White House has proposed expanding the commission from six to eight members, thus allowing two of Reagan's nominees to have seats without displacing any commissioners.

However, civil rights groups have objected to the proposal, arguing that it breaks with "pattern and practice" for no reason. One civil rights activist who objected said the proposal would "reward" Reagan by allowing him to name four of the eight commissioners. The president earlier named two of the current commissioners.

Abram, a New York lawyer, refused comment yesterday. Dr. John Bunzel, another commission nominee and a senior fellow at the Hoover Institute, said he is "keeping out of it." The third nominee, Robert Destro, a Catholic University law professor, said he has not spoken with Abram recently but that he, too, objects to having Abram replace Saltzman.

"That kind of deal starts to look like a quota," Destro said. All of Reagan's nominees share his opposition to quotas.