White House officials sought to explain yesterday a contradiction between President Carter and Attorney General Griffin B. Bell on the handling of the criminal case against former Central Intelligence Agency Director Richard M. Helms.

Bell told reporters Tuesday that he had met with the President at the White House on July 25 and received his authorization to explore the possibility of plea bargaining with Helms in order to avoid a trial at which sensitive national security information might be revealed.

However, more than two months later, at a news conference Sept. 29, Carter said flatly that Bell had not consulted with him on the Helms case. Asked about his own view of the case at that time, the President replied.

"He Bell has not consulted with me, nor given me any advice on the Helms question. I am familiar with it through reading in the press. I have no way to know yet the strength of the possible indictment or charges."

Yesterday, White House deputy press secretary Rex Granum offered this explanation for Carter's failure to mention the July 25 meeting and his assertion that he had not discussed the case with Bell.

Although the July 25 meeting was private and not announced at the White House, the President had been told that his press secretary, Jody Powell, had discussed it with some reporters. Therefore, he assumed the fact that the meeting was held was public knowledge. When Carter said Sept. 29 that Bell had not consulted him about the case, he meant he had not talked to Bell about it since July 25.

"That is the President's recollection" Granum said.

Asked if Carter's Sept. 29 news conference statement was misleading, Granum said, "I will leave that up to your own analyses."

The plea bargaining which Carter set in motion last July culminated Monday in Helms' plea of "no contest" to two misdeamor criminal charges for failing to testify fully, and accurately to a Senate committee about the CIA's activities in Chile.

On other topics, Granum said that a nationally televised speech on energy, which Carter had planned to deliver tonight would be made later. He said no date had been set, but that it would be seen.

Granum also said that the President has no plans to withdraw the nomination of Sam Zagoria to a Republican seat on the Federal Election Commission, and denied a charge by GOP congressional leaders that Carter had broken a promise to them in nominating Zagoria.

Granum said the President never promised Senate Minority Leader Howard H. Baker Jr. (R-Tenn.) or House Minority leader John J. Rhodes (R-Ariz.) that he would fill the republican vacancy on the FEC from among a list of nominees recommended by them.

Zagoria, an official of the U.S. Conference of Mayors, was recommended to the White House by five generally liberal Republican senators. He was not the choice of Baker of Rhodes.