Speaking at law school ceremonies where students had proclaimed it "Dave Marston Day," Attorney General Griffin B. Bell said in Portland, Ore., Thursday night that he'd considered resigning during the controversy because he felt he'd let President Carter down.

Bell told a press conference at the dedication of a new legal research center for Lewis & Clark College Law School that he felt he had failed the President in not knowing who was being investigated by the office of David W. Marston, former U.S. attorney in Philadelphia.

Bell dismissed Marston, a Republican appointee, Jan. 20, after Carter agreed to expedite the prosecutor's ouster at the urging of Rep. Joshua Eilberg (D-Pa.). Both Eilberg and Rep. Daniel J. Flood (D-Pa.) have come under investigation as the result of an inquiry initiated by Marston's office into the financing of a $65 million hospital construction project in Philadelphia.

The attorney general has told associates he finally decided against resigning because he felt he hadn't done anything wrong.

Students at the law school, where Bell had agreed to be the speaker at the dedication of a new $2.7 million research center, had spontaneiously dubbed it "Dave Marston Day" and some of them were said to be wearing "Marston" buttons when Bell arrived.

Calling the case one or "utter confusion," Bell said he intended to make "all of the facts available to the American public" when a Justice Department investigation now under way is completed.