Among Charlotte-area warehouses and distribution centers, vacancy rates are rising. Rents are falling.

Yet two local developers are betting now is the time to build more than 300,000 square feet of new industrial space.

Making the projects particularly noteworthy: They're being built on a speculative basis, meaning there are no guaranteed tenants at a time when companies are scaling back or shutting plants.

Could the industrial market be poised for a rebound?

"It's definitely a promising sign," said William Wheaton, research manager with CoStar Group, which collects and analyzes commercial real estate data. "It's about time they start building again."

Industrial development picked up in 2007 but came to a halt this year, with Mecklenburg County issuing only three industrial building permits as of Sept. 30, compared with 25 issued during the same time last year. So far this year, developers have added 112,000 square feet of industrial space in Mecklenburg County, down sharply from 1.5 million in 2007, according to Karnes Research.

At SilverLanding in west Charlotte, concrete is being poured for the first of what is planned to be five LEED-certified buildings near the intersection of Steele Creek Road, N.C. 160 and Interstate 485. Warren Snowdon and Ralph Oldham, both of Commercial Carolina/Cushman & Wakefield, are marketing more than 125,400 square feet of space, available first quarter next year.

About a half-hour drive north in Concord, land is being graded for the Nolim Group SA Inc.'s 390 Business Boulevard warehouse, a 176,000-square-foot building in The International Business Park.

The developers and brokers behind the speculative projects say they don't expect to fill their buildings quickly. Instead, they said, they are positioning themselves for 2010 or 2011, when the economy is expected to have improved. Already, they said, they are receiving more nibbles from prospective tenants than expected, a trend other area brokers say they're seeing, too.

Brokers say the interest is primarily coming from mid-range users, those interested in leasing between 30,000 and 75,000 square feet. Most companies are already operating in the region. Some are looking to consolidate.

"Next year may not be a great year, but we hope to be ahead of competitors," said Snowdon, the leasing agent for SilverLanding. "We're seeing folks looking very early."

Said Bryan Crutcher of CB Richard Ellis in Charlotte, who is marketing 390 Business Boulevard: "We're against the trend of other developers for sure."

To be sure, struggling companies continue to downsize or shutter factories, boosting vacancy rates.

Charlotte-area vacancy rates rose to 12.9 percent in the third quarter, up from 11.3 percent in the second quarter, according to CoStar, which tracks 14 N.C. counties and three S.C. counties. In Mecklenburg County, the vacancy rate hit 14 percent, up from 11.3 percent last year, according to preliminary numbers from Karnes Research. Charlotte's vacancy rate is higher than the national average of 10 percent. The market is considered to be in balance when vacancy rates hover around 10 percent, experts say.

However, some newly released third-quarter numbers point to encouraging signs.

The time it takes to lease or sell a property is falling: Days on market dropped from 304 days in fourth quarter 2008 to 230 days in the third quarter, according to CoStar.

Another key figure brokers use, net absorption, or the amount of space occupied minus the space vacated, was negative 3.2 million for the third quarter. Exclude the 3.2-million-square-foot Concord plant that Phillip Morris USA closed and absorption turns positive for the first time since third quarter 2008, according to CoStar.

"The third quarter was actually pretty strong," Wheaton said.

Charlotte's industrial market has fared relatively well during the recession compared with the office and retail markets because developers didn't overbuild, said Karnes analyst Andrew Jenkins. One reason is developers grew cautious when industrial vacancy rates peaked at 19.2 percent in 2003, Jenkins said, "scaring everyone into being careful where they built."

SilverLanding's owner, M. David Properties of Charlotte, purchased the land in 2001, wanting to be close to the airport, interstate and railroad. Charlotte is the Southeast's second-largest distribution hub, behind Atlanta.

Manager Lorin Silverman Stiefel said the group had to start building this year for tax reasons. Otherwise, she said, the company might have waited until the economy was on better footing. Ultimately, she thinks building now will prove to be a wise move. The developer is securing a bank loan but will pay for most of the building's shell with cash.

She's optimistic companies will come looking for space so close to multiple forms of transportation.

"Nobody has anything they're building now," she said. "If you can afford it, it's probably a smart time to build."

In Concord, 390 Business Boulevard is expected to be ready by the first quarter. Crutcher, the leasing agent, said Cabarrus County needed more industrial space catering to distributors who use large trucks and need 30-foot-tall ceilings to store inventory.

Much of the space built in Cabarrus County in recent years has grade-level doors to service racing-related companies, Crutcher said.

"We feel we've bottomed out," Crutcher said. "We think there is pent-up demand for larger space, for relocations."