The administration's civilian and military intelligence agencies sought to present a common front yesterday on the question of Soviet military spending, but newly reported statements by a Pentagon official appeared to keep open the gap between them.

The Central Intelligence Agency issued a five-paragraph press release emphasizing that despite a slowdown in the growth rate of Soviet defense spending, Moscow continues to outspend the United States by substantial margins "overall and in important specific categories."

The CIA release was handed out by the Defense Department, whose Defense Intelligence Agency has publicized higher Soviet spending estimates than those of the civilian CIA. The CIA release was handed to Pentagon reporters with a brief message saying that it was "coordinated with the Department of Defense" and that "the Department of Defense endorses the analysis."

At the same time, Harvard University's Russian Research Center made available a speech there Feb. 14 by Norbert Michaud, chief of the strategic defense economics branch of DIA. Michaud said his agency estimates a Soviet increase of 5 to 8 percent in Soviet procurement of major weapons systems in 1983, measured in dollar terms, and "further increases" in 1984.

These increases were highlighted by a major Soviet shipbuilding program in 1983 and aircraft purchases in 1984, Michaud said.

Acknowledging differences with CIA estimates, Michaud said his agency is "basically using CIA prices" for Soviet weapons, adjusted for a "learning curve" he did not explain. Michaud said the main difference between the two intelligence agencies is over the quantity of Soviet weapons estimated to have been procured.

CIA Deputy Director for Intelligence Robert Gates, in congressional testimony released Thursday, referred to "a stagnation in Soviet spending for military procurement after 1976" which lasted for "at least seven years from 1977 to 1983."

At another point Gates said the preliminary CIA estimates for 1983 "suggest that procurement may have experienced some modest growth over 1982." He described this conclusion as "tentative" because of the difficulty in estimating the distribution of costs over time and said another year of data is required before reaching conclusions about what is happening.

Gates' testimony, delivered in secret last Nov. 21, said the rate of increase in overall Soviet military spending "dropped appreciably, to about 2 percent per year" beginning in 1977. This was about half the growth rate that the CIA had been projecting before a major reevaluation of Soviet military spending in 1983.

In its statement yesterday, the CIA said Gate's testimony as released by the Joint Economic Committee "presents a narrow view of Soviet military growth." Emphasizing what it called "the broader context," the CIA said that despite the decline in the Soviet growth rate, the cost of Soviet defense activities "has exceeded that of the United States by a large margin."

In 1981, the CIA said, the dollar cost of Soviet defense activities and of Soviet procurement exceeded the comparable U.S. figures by 45 percent. The agency said this has "narrowed" since 1981 but that "the Soviets still outspend the U.S. overall and in important specific categories by substantial margins."

The CIA said that in 1977 through 1983 the Soviets added 1,100 land-based intercontinental ballistic missiles, more than 700 submarine-launched ballistic missiles, 300 bombers, 5,000 fighter planes, about 15,000 new tanks and "substantial numbers" of ships and submarines. It said the United States in the same period added 135 land-based intercontinental ballistic missiles, 390 submarine-launched ballistic missiles, no bombers, 3,000 fighter planes, 5,000 tanks and 106 major warships.

Compared with the CIA estimate of 2 percent annual growth in overall Soviet military spending, measured in 1970 rubles, the Center of Defense Information provided data for the growth in U.S. overall military spending measured in 1970 dollars. The U.S. increases were: l979, 3.4 percent; 1980, 2.6 percent; 1981, 4.6 percent; 1982, 7.5 percent; 1983, 7.8 percent; 1984, 4.05 percent; 1985, 7.5 percent; 1986 (requested), 8.1 percent.