After months of speculation that it might leave downtown, Dallas’ largest business — telecom giant AT&T Corp. — says it will stay in its headquarters on Akard Street and spend millions of dollars on a reboot.

The company also says it intends to add more than 1,000 workers downtown over the next few years.

Keeping AT&T downtown was a top priority for Dallas, said Kourtny Garrett, president of the economic development group Downtown Dallas Inc.

“Absolutely they could have left,” Garrett said. “They are an international corporation with options all over the globe.”

AT&T, which has about 5,700 workers in its four-building complex at Commerce and Akard streets, moved here from San Antonio in 2008.

Earlier this year, the company hired real estate firm CBRE to look at long-term office needs for the company.

“We went through and looked at a significant number of options,” AT&T chief financial officer John Stephens said. “But we are very pleased with the location here and very optimistic we can come up with a great plan for us to stay right here.

“Our employees like this facility and being in the heart of Dallas,” Stephens said.

AT&T has more than 2 million square feet of facilities along Akard Street in buildings built between 1929 and 1984.

The company has been investing money in the properties over the last eight years. “We have spent well over $100 million in improvement on the interiors and exteriors,” Stephens said.

AT&T didn't detail how much more it will spend to upgrade its complex but said it will cost millions of dollars.

The largest contingent of AT&T workers is in the 37-story Whitacre Tower on the south side of Commerce Street. That building has two large public plazas on Akard and Browder Streets.

AT&T plans to upgrade those pedestrian areas, adding landscaping, lighting and other features.

“We not only want to give our employees a great place to work; we want to provide an outdoor destination for other workers, local residents and visitors,” Stephens said.

AT&T says it also plans to add more restaurant and retail outlets, an outdoor event space and public art.

It’s calling the complex the AT&T Discovery District.

Stephens said AT&T is working with the city of Dallas, Dallas Area Rapid Transit and Downtown Dallas Inc. to develop a long-term plan for its downtown complex.

“When we moved [here] in 2008, we had about 2,500 employees,” Stephens said.

“That number has more than doubled, and we are looking getting the number of people working in our buildings to more than 7,000 here in the next couple of years.

“We want to make this a great place for our employees who work hard,” he said. “We want to have a nice place for those who visit us, live downtown and come down here.”

Real estate brokers said AT&T looked at several new buildings for its headquarters and considered at least one location in the suburbs.

“To see them renew that confidence in downtown now is demonstrative of the strength in the market and their commitment to Dallas,” Garrett said.

With more than $160 billion in annual revenue, AT&T is the largest company based in Dallas and the second largest in all of North Texas, behind only Irving’s Exxon Mobil Corp.

It has more than 275,000 workers worldwide.

AT&T is the name brand sponsor of the Dallas Cowboys stadium in Arlington and the performing arts center in downtown Dallas’ Arts District.

The company’s ongoing headquarters hiring has helped boost the revitalization of downtown, Garrett said.

“The young professional talent we are seeing is great,” she said. “They are going to draw the type of employees who are predisposed to support downtown.

“They will choose to live there and populate our restaurants.”

Garrett said the improvements AT&T makes to its headquarters campus will strengthen that area.

“The location they are in is critical,” she said. “They are in the southern portion of downtown between the Main Street area and the civic district.”

AT&T’s neighbor across the street — the landmark Adolphus Hotel — is spending more than $40 million to upgrade its more than century-old building.

Dallas Mayor Mike Rawlings said the city will support AT&T as it invests in downtown.

“It is important that the city of Dallas works to ensure this great corporate citizen, which has done so much for our community, remains in Dallas,” Rawlings said.

AT&T said it will ask the city to make changes in the streets surrounding its buildings to improve pedestrian safety and traffic flow.

The company expects all the improvements to be a multiyear project.

“But we are looking to move very quickly in collaboration with the city,” Stephens said. “Dallas has been a great place for us and a wonderful environment.”