Oahu office building owners with space available for lease are generally still in a tough spot despite good growth in the local economy, according to a new report released for publication today.

Commercial real estate firm Colliers International projects in its report that occupancy in Oahu’s office rental market will decline this year after an unstable first two quarters.

A decline, if realized, would follow a slight gain last year and a small loss the year before.

Through the first half of this year, occupancy rose by 16,892 square feet after 80,590 square feet of available space was filled in the first quarter, followed by an emptying of 63,698 square feet of space in the second quarter.

“While many landlords had hoped that the market was beginning to stabilize and generate healthy traction, the second-quarter performance confirmed that the office market volatility is likely to persist,” the report said.

Colliers said market conditions that include an expanding local economy and job growth suggest that companies should be needing more office space on the island. Typically, a business can use 150 to 200 square feet of office space for every new job, but Colliers said the addition of 13,200 jobs in the local office sector since 2010 coincided with the loss of 391,423 square feet of occupied office space.

“We had hoped the office market would gain traction with the recent solid job growth, but unfortunately volatility remains, as the vacancy rate rose for the first time in three quarters,” Neal Hafner, a senior associate with Colliers, said in the report.

The vacancy rate at midyear was 13.1 percent, which represented 1.9 million square feet of vacant space out of 14.7 million square feet of leasable space. At the end of March, the vacancy rate was 12.2 percent.

Oahu’s office vacancy rate has hovered roughly around 12 percent or 13 percent since 2010.

One trend that has been hampering growth in occupancy for Oahu office building owners that lease space is a move by tenants acquiring their own property, Colliers said. In other cases, government agencies have moved out of private-sector space. In the second quarter, one vacancy was created when World Gym vacated about 15,000 square feet in the Kamakee Vista office building in Kakaako, Colliers noted.

Colliers said average base rental rates being asked by landlords ticked up to $1.70 from $1.67 per square foot per month over the last two quarters, which the company said is linked to higher demand by tenants for space in East Oahu, Leeward Oahu and Windward Oahu.

In urban Honolulu’s central business district, rents have been on a downward trend since 2008, Colliers said, adding that the average negotiated base rent in this area is closer to $1.27 per square foot per month.

The midyear vacancy rate in Honolulu’s central business district was 14.9 percent, which was the highest in 20 years for the area and higher than eight other districts on Oahu defined by Colliers.

The Kakaako/Kapiolani/King district had the next-highest vacancy rate at 14.2 percent, followed by the airport/Mapunapuna area at 11.5 percent. The lowest vacancy rates were 3.6 percent in Windward Oahu and 4.3 percent in East Oahu.