Work on the $10 million addition is scheduled to begin in about a month and be completed in December, said R.H. Lovin Jr., Covenant's vice president of administration.
"The company is bursting at the seams," Lovin said.
Plans call for adding the 600 new employees gradually through 2005. Covenant has 450 employees at its 80,000-square-foot headquarters, located off Interstate 24 in Lookout Valley. Nationwide, the firm employs about 4,850 workers, including 4,000 drivers.
Lovin said the new employees will be a mix of professional and clerical workers.
The company set another profit record in its latest quarterly earnings, earning $6.7 million, or 45 cents per share, the company reported.