Senior Pentagon officials, seeking internal approval for a tentative plan to deploy ballistic missile defenses in the mid-1990s, pressured an advisory panel to omit sharp criticism of the plan in a recent key scientific report, military and congressional sources said yesterday.

A recent report by a Defense Science Board panel concluded that the Pentagon's Strategic Defense Initiative (SDI) deployment plan endorsed by Defense Secretary Caspar W. Weinberger was so "sketchy" that neither its price nor its effectiveness could be determined.

This criticism was omitted from a version of the report given to the Defense Acquisition Board, the Pentagon's senior decision makers on new weapons systems.

The science panel also recommended that the board withhold deployment-plan approval "for the next year or two" while SDI officials try to fill substantial "gaps in system design and key {missile defense} technologies."

But this recommendation also was omitted from the acquisition board's copy of the report, according to Pentagon and congressional sources, who provided The Washington Post with a full copy.

Aides to Undersecretary of Defense Richard P. Godwin, acquisition board chairman, confirmed the omission yesterday, but said it was made before he got the report from panel chairman Robert Everett, a former president of MITRE Corp., a Pentagon contractor.

Everett said in an interview that he deleted the passage after discussing it with Godwin, but without informing all the panel members. "Nobody put any pressure on me," Everett said, adding that he and Godwin agreed "we were not asked to comment" on whether the acquisition board should grant its approval for the deployment plan.

But knowledgeable sources said the panel was explicitly chartered to examine the deployment plan's "readiness" for approval.

Board approval is a crucial part of an early deployment scheme that calls for thousands of ground- and space-based rockets to be positioned to shoot down Soviet missiles.

At issue before the board, which includes senior officials of the three military services, is whether SDI research should be intensified and sophisticated experiments conducted to prove underlying technologies. SDI officials also see board approval as a means of winning more support from Congress.

But the science board panel concluded the plan was too vague and that a decision should await additional research.

In the versions given to acquisition board members, the advisory panel also implicitly challenged Weinberger's desire to conduct realistic missile defense tests under a controversial "broad" interpretation of the 1972 Antiballistic Missile Treaty.