Hundreds of orange robots will traverse the vast aisles of Amazon's coming fulfillment center in north Houston, dramatically speeding up the amount of inventory prepared for shipping each day.

But these machines are no job killers. The online retail giant on Tuesday also increased the number of human jobs it expects to add in its effort to meet growing demand and hasten delivery throughout the region.

The company now expects to hire 2,500 full-time employees to staff the massive warehouse under construction in the Pinto Business Park at the southwest corner of Interstate 45 and Beltway 8. That's more than double the number of jobs it announced last year at the outset of the project. At the time, Amazon said it expected to hire at least 1,000.

The facility, expected to open this summer, will be equipped with robots that fetch inventory within minutes for warehouse workers tasked with packing and shipping the goods. The technology requires more hands on deck to keep up with the fast-moving process and boost output, spokeswoman Ashley Robinson said.

"Customer demand is expected to increase," she said. "We need to hire more folks to make sure we can keep up."

Amazon is investing $136 million in the 855,000-square-foot warehouse, which will fulfill orders for smaller items such as books, electronics and toys. It will stock well more than 15 million items, Robinson said, giving local customers access to a greater assortment of goods available for rapid delivery.

The fulfillment center will be Amazon's seventh in Texas and the first in Houston. Locally, the company operates a sorting center in Humble, as well as a separate, rapid-delivery Prime Now hub in the area. But many local orders are handled by Amazon operations in the Austin-San Antonio area.

The Houston facility is expected to provide a substantial economic boost to the area around Greenspoint Mall that recently was rechristened as the North Houston District.

The mall, long the largest retail development in the area, is mostly vacant. Major employers including Exxon Mobil have relocated in recent years. Many residents have moved to other suburbs.

The district highlighted the area's location and demographics as it sought an investment from the e-commerce giant.

Robert Fiederlein, the district's vice president for strategic planning and development, said many of the residents in the area's 18,000 apartment units might be interested in warehouse jobs with benefits and few specialized skill requirements.

"We are a working-class neighborhood," he said. "Our thinking was a lot of folks that live in this area might be suitable for employment at this type of facility."

Amazon ultimately secured substantial incentives to invest in the area. Harris County commissioners last year granted the company a 10-year tax break expected to save it nearly $180,000 annually.

The updated hiring goals exceeded the district's expectations. Fiederlein said it looked at other Amazon fulfillment centers in Texas and felt the local development would create as many as 2,000 jobs.

"We're glad to hear it's a little higher than we were expecting," he said. "To us, the jobs are the bottom line in a community like ours."

Amazon has for years pioneered the use of warehouse robots, meant to aid workers and create a more efficient process. The company in 2012 acquired robotics manufacturer Kiva Systems for $775 million as such technology became more prevalent throughout the sector. The robots now roam about 25 Amazon fulfillment centers worldwide, including five in Texas.

The company has plans to further expand its Houston-area presence. Waller County earlier this year offered Amazon tax incentives to build its 10th Texas fulfillment center in Katy. That is expected to create 1,000 full-time jobs in a 1 million-square-foot facility on 80 acres near Woods Road and Interstate 10.

The hiring news came amid a milestone for the company. Its stock on Tuesday topped $1,000 a share for the first time, reflecting years of rapid expansion.

Rising online sales have fueled the growth. Amazon exploded from 30,000 U.S. employees in 2011 to more than 180,000 at the end of last year, when its share of the U.S. e-commerce market neared 40 percent, according to a recent report by J.P. Morgan Chase. The firm expects it to claim half of the market by 2019.

Earlier this year, Amazon announced plans to boost its domestic workforce by more than a third by hiring 100,000 full-time U.S. workers in an 18-month period.