Office vacancy rates nationally in both downtown and suburban markets declined in the first quarter of 1989, but Salt Lake City was one of the few metro areas showing increases, reports Los Angeles-based real estate firm Coldwell Banker Commercial Group.

Vacancy rates on March 31 were 16.1 percent for downtown areas, down from 16.2 percent for the previous quarter and 16.3 percent in March 1988. For suburban areas the rate was 21.4 percent, down from 21.5 percent for the previous quarter and 22.3 percent a year ago.The new national downtown rate was the lowest since the second quarter of 1985.

Total absorption in downtown markets for the quarter was 4.8 million square feet. Out of 46 downtown markets surveyed, 22 showed declines in vacancy, the sharpest being Kansas City, Tampa and Indianapolis. Some large increases were recorded in Phoenix, Hartford and San Francisco.

In suburban markets, total absorption in the period was 16.5 million square feet. Coldwell Banker surveyed 50 suburban markets, finding declines in 29, the sharpest being in San Jose, Northern New Jersey and Austin, Texas.

Increases were posted in Salt Lake City, Detroit and Toronto.