Dallas-based AT&T plans to lay off up to 54 employees at a call center in Richardson by the end of March.

The telecom company disclosed the cuts in a letter to the Texas Workforce Commission. Companies are required by law to report layoffs, depending on size and scope.

AT&T spokesman Marty Richter said the affected employees work part-time and monitor quality control for customer calls about AT&T products, such as U-verse and DirecTV. He declined to say how many people work at the Richardson office, but said it will stay open.

"We're adding people in many areas where we're seeing increased customer demand for products and services," he said Monday in a statement. "However, as we continue to do everything we can to better serve our customers, some restructuring is occasionally necessary in order to reduce redundancy and improve efficiency."

The layoff is the latest downsizing at AT&T, as the company shifts its focus from legacy services, such as landline phones, to growing areas like business services and entertainment. The company is also undergoing a massive retraining program to teach employees new skills and prepare them for jobs of the future. Employees can get certifications or full degrees through affiliations with schools, such as Georgia Tech.

AT&T's employee count decreased by about 13,000 people -- or about 5 percent -- in a year, according to the company's earnings report for the fourth quarter of 2016. It shrank from 281,450 people at the end of 2015 to 268,540 people at the end of 2016.

AT&T spent $344 million on employee separation-related expenses in 2016, according to AT&T's earnings report.

A smaller workforce is a side effect of advancing technology, said John Donovan, chief strategy officer and group president for AT&T technology and operations. In an interview last fall, he said "as technology improves, productivity improves and you don't need as many people."

AT&T eliminated an undisclosed number of management jobs last fall. The company would not say which divisions or locations were affected, but made the cuts before the end of 2016.

Despite staffing changes, Richter said Monday that AT&T continues to grow in Texas. AT&T hired nearly 3,700 people in the state in 2016, including about 110 people in Richardson, he said. It's currently hiring over 200 more people across the state, he said.