The former head of Vietnam intelligence for the Central Intelligence Agency testified today that he wrote a cable in September 1967 accusing retired Army general William C. Westmoreland's command of "stonewalling, obviously under orders" against CIA efforts to increase estimates of enemy troop strength.

But George A. Carver Jr. also said that, when he met with Westmoreland two days later, the general "immediately, firmly and emphatically" denied imposing any ceiling on his officers negotiating differences between the CIA and the military over an official such estimate.

Carver was then the CIA's special assistant to the director for Vietnamese affairs. He was testifying for a third consecutive day in Westmoreland's $120 million libel action against CBS, Inc., and three co-defendants.

At issue is whether a CBS documentary was correct two years ago in accusing Westmoreland of ordering an arbitrary ceiling of 300,000 on numbers of enemy troops and of coopting officers under him at Military Assistance Command, Vietnam (MACV) and other intelligence officers, including those at the CIA, to stay within that range, which had been cited by the media.

The CBS broadcast said that, because of a conspiracy to underrate the enemy in the autumn of 1967, the media, the public and even Westmoreland's superiors, including President Lyndon B. Johnson, were surprised by the massive communist attacks that began throughout South Vietnam on the Tet holiday Jan. 31, 1968.

In the program, "The Uncounted Enemy: A Vietnam Deception," narrator/reporter Mike Wallace said that, after a bitter intelligence debate on troop estimates, "Gen. Westmoreland . . . won the intelligence war.

"And so, instead of being told of an enemy army of more than a half a million, the president, the Congress and the American public were told there were only 248,000 Viet Cong left, that the enemy was running out of men," Wallace reported.

In cables, parts of which were read to the jury by Westmoreland's attorney, Dan M. Burt, Carver described how he engaged in "heated, testy and at times adversarial" arguments with then-Army brigadier general Phillip Davidson, Westmoreland's second-in-command at MACV and chief of intelligence.

Carver said these occurred at a meeting in Saigon in September 1967 to hash out a CIA-Army dispute about enemy strength.

But, after four days of the negotiations, Carver said, in a cable to CIA Director Richard Helms: "I have made a major concession in not quantifying the irregulars. It seemed to me this was MACV's major sticking point."

Thus, an earlier CIA estimate of 120,000 so-called irregular troops, including the "home militia" of women, old men and teen-agers, was not listed numerically in the enemy Order of Battle but merely included in a written summary of enemy strength.

In another cable to Helms, Carver said the official National Intelligence Estimate hammered out that week would not include a total of Viet Cong military and political troops "since we believe such an aggregate total is inherently meaningless and misleading."

Carver's cables, some of which were read here, are colorful and highly descriptive of the confrontation in the summer and fall of 1967 among intelligence officials from all branches of government.

In the series of cables, most labeled "Eyes Only" for Helms, Carver charted the compromise, always suggesting that he would try to see Wesmtoreland to attempt to "loosen this straitjacket" imposed by MACV on the negotiations.

In a cable dated Sept. 13, 1967, after Carver met with Westmoreland, he told Helms: "Circle now squared . . . we now have agreed set of figures Westmoreland endorses."

Those aggregates, minus the irregulars, were increased from an earlier MACV figure of 298,000 at the beginning of the session to a range of 299,000 to 334,000 as the compromise.

In the cables, Carver accuses Davidson of interrupting him "frequently and sometimes tendentiously" during sessions.

Carver seems to relish "discomfiture of our MACV hosts" when the CIA's case seems bolstered and describes "tacit or oblique lunchtime and corridor admissions by MACV officers, including Davidson -- all point ing to inescapable conclusion that Gen. Westmoreland . . . has given instruction tantamount to direct order that Viet Cong strength total will not exceed 300,000 ceiling."

Asked today about such language, Carver said: "I had had two extremely frustrating days, very difficult discussions where I felt the people with whom I was talking, discussing, were being singularly unreasonable since they were not doing things my way."

"I was tired, I was irritated and I lapsed into slightly purple prose trying to convey a mood and impression, having no thought I would be discussing this in detail 17 years later in a lawsuit," Carver added.

Carver, whose role was considered crucial in any compromise on enemy troop figures, is expected to face cross-examination by CBS attorney David Boies Tuesday.

Westmoreland is expected to testify next week.