Republican efforts to move a tuition tax credit bill to the Senate floor were stymied yesterday when Democrats on the Finance Committee said they were not satisfied yet with its anti-discrimination provisions.

Committee Chairman Robert J. Dole (R-Kan.) postponed a mark-up on the administration proposal to give credits to parents whose children attend private schools after objections by Sens. Daniel Patrick Moynihan (D-N.Y.) and Bill Bradley (D-N.J.).

Sen. Bob Packwood (R-Ore.) had proposed that the bill be reported without amendment and any further anti-discrimination provisions be added on the floor.

When the mark-up began Monday, members said that strong language in the committee report would be enough to make sure that credits would not be used to support schools that discriminate on racial or other illegal grounds.

Bradley, however, said yesterday that he thought it was the committee's responsibility to reassure itself on the issue before the bill is reported out.

Moynihan expressed disbelief that no representative of the Justice Department was present. "The Justice Department is not here when they know that the heart of our concern is this subject."

In setting the bill aside again, Dole said, "If we don't solve the disrcimination problem there may not be any mark-up."

Moynihan said that the concern about the bill's anti-discrimination rules stems from the administration's decision in January to change its position in the Supreme Court and argue that the Internal Revenue Service doesn't have authority to deny tax exemptions to private schools that discriminate. The case will be heard this fall with an outside lawyer defending the old IRS position.

Another mark-up attempt is possible later in the week, committee aides said.