Soviet defense spending did noi rise as quickly as anticipated from 1976 through 1981, but it is too early to tell whether this will be a long-term slowdown, government officials said yesterday.

The CIA and Defense Intelligence Agency, these officials said, expected the historic 3 percent real annual growth to prevail during the 1976-81 period, but it dropped to about 2 percent.

The officials, who under rules of a Pentagon briefing could be identified only as senior Soviet specialists, denied press reports that the two intelligence agencies had any disagreement over the growth rate.

Additional information on what the Soviets spent from 1976 through 1981 has confirmed that the smaller yearly increases were more than the "hiccup" they appeared to be at first glance, the officials said.

However, they cautioned that the Soviets may be gearing up for producing new models of planes, tanks and other weaponry which would bring them back up to the 3 percent annual growth rate in the future. The officials said the average 2 percent growth from 1976 through 1981 does make it easier for the United States to close the current gap in weaponry.

"They will not race away from us completely," said one official in reporting what he termed "the tentative good news."