An engineering design firm working on a massive overhaul of central Maine’s power grid is opening an office in Portland that will be staffed with about 80 people, the company said Wednesday.

Burns & McDonnell, based in Kansas City, Mo., opened an office in New Gloucester in 2008 that employs about 80 workers.

Most of those workers will relocate to Portland from New Gloucester, where the company said it will maintain a smaller office.

The firm’s primary focus in the state has been working as program manager for Central Maine Power Co.’s Maine Power Reliability Program, a $1.55 billion upgrade of the electric utility’s infrastructure that began in 2009. That project is scheduled to wrap up by mid-2015.

The company said it has been recruiting and hiring local talent in Maine and will continue to seek qualified workers for its Portland operation.

“This same group joins our excitement in committing to call Maine home for the future,” company officials said in a news release.

The firm plans to celebrate the opening of its Portland office at 27 Pearl St. on Thursday with an open-house event featuring employees, local business leaders and government officials, including Portland Mayor Michael Brennan.

Founded in 1898, Burns & McDonnell provides engineering, architecture, construction, environmental and consulting services to clients throughout North America and abroad.

The employee-owned company has a staff of about 4,000 engineers, architects, scientists, planners, estimators, economists, technicians and other professionals in 20 offices throughout the U.S.

Burns & McDonnell was ranked No. 18 this year on Fortune magazine’s list of America’s top 100 companies to work for.

J. Craig Anderson can be contacted at 207-791-6390 or:

canderson@pressherald.com

Twitter: @JCraigAnderson