Some national retailers are closing stores amid weakening consumer confidence and a slowing economy, but that hasn't had a negative effect on O'ahu's retail landscape as measured by the amount of store space leased to retailers.

Over the past five months, dramatically more occupied retail space was added on O'ahu, according to a new survey by Colliers Monroe Friedlander.

The Honolulu-based commercial real estate firm said O'ahu retail vacancy has been stable this year to date, with the amount of empty space up just barely from 3.33 percent at the end of last year to 3.35 percent this month.

At the same time, Ala Moana Center opened a new wing anchored by Nordstrom to add about 300,000 square feet of leased and near fully occupied space, though because it was largely filled by tenants when completed earlier this year the addition had no significant effect on the vacancy rate.

"At this point, the retail market still appears to be healthy with vacancy rates holding steady as new occupancy growth is boosted by delivery of new retail projects," the report said.

Still, retailers are concerned about the slowing economy and recent shocks to Hawai'i's visitor industry from the shutdowns of passenger carriers Aloha Airlines and ATA Airlines.

Mike Hamasu, consulting and research director for Colliers, said retail is an industry that typically shows weakness six to nine months after economic difficulty such as major job or population losses or decreased personal income.

Rising gas and food prices that siphon discretionary income from consumers present added concerns for many retailers, but Hamasu said the local retail industry should maintain stability this year.

"I don't see any large-scale closures," he said. "We've probably reached a plateau."

O'ahu's 3.35 percent retail vacancy represented 387,791 square feet of empty space out of 11.6 million square feet of tenant space at shopping complexes counted by Colliers. Five years ago, retail vacancy was about 8.5 percent.

Nationally, several retail chains recently announced plans to close stores in the face of financial struggles. Among retailers that in recent months announced store closure plans were Footlocker (140 stores), Linens 'n Things (120 stores), Zales (105 stores) and Sharper Image (90 stores).

On O'ahu, major movement in retail space this year included the closures of CompUSA stores in Kaka'ako and Pearl City that were more or less offset by openings of Steve & Barry's in Waikele and Office Depot in Waipahu.

Several smaller retailers also opened stores at Waikiki's largest shopping mall, Royal Hawaiian Center, which is finishing up a $115 million renovation, and at Pearlridge Center where more space was filled where J.C. Penney closed in 2003.

In tandem with the flatness in occupancy this year, landlords have ceased asking for significant increases in rent, Colliers reported.

The average monthly rent (including maintenance fees, taxes and insurance) being asked by shopping center owners outside premium spots of Waikiki and Ala Moana Center is $3.38 per square foot, up from $3.31 at the end of last year. In 2003, the average asking rent was $2.35.

"This is a sizeable slowdown after having posted three years of double-digit rent increases from 2004 to 2007," the report said.

O'ahu's relatively low retail vacancy rate has made it difficult for new or expanding retailers to find suitable space, Colliers said.

Developers plan to build more than 3 million square feet of new retail space, including regional malls Kapolei Commons and Ka Makana Ali'i in the 'Ewa-Kapolei region, though those two large projects are a year or more away from fruition.

The 610,000-square-foot Kapolei Commons is slated to open early next year anchored by Target, Circuit City, OfficeMax, Petco, Sports Authority, Borders Books and Music and a 15-screen Regal Cinema.

Ka Makana Ali'i, a planned regional mall with 1.1 million square feet of space in East Kapolei is more tentative and has not announced prospective anchor tenants.