The Reagan White House is resisting efforts by the chief prosecutor in the Iran-Contra case to use certain classified national security information in the trial of Oliver L. North.

The White House made its position known to independent counsel Lawrence E. Walsh, the chief prosecutor in the case, "earlier this week," a senior administration official said Wednesday. The official provided the information on grounds he not be identified publicly.The source would not say how much information the White House wants withheld. He said the move to block the release of certain information was made on "national security grounds" but would not say what other actions the executive branch might take to protect its secrecy.

U.S. District Judge Gerhard A. Gesell had told the Reagan administration last week that he would have little control over the flow of secrets once the trial begins, possibly in late January.

The official said the White House move was not an attempt to help North, a former National Security Council deputy, scuttle the prosecution's case against him.

The White House position was made known as closed hearings began on some of the classified documents in the case.

Gesell conducted the hearing to consider the former presidential aide's objections to deleting sensitive references from 350 classified documents that Walsh wants to use as evidence.

North objects to virtually all of the proposed deletions, arguing the references to countries, foreign officials and U.S. intelligence agents are necessary to defend charges that he conspired to divert more than $14 million in U.S.-Iran arms-sale profits to the Contra rebels in Nicaragua.