In what could be one of the largest leases in metro Atlanta this  year, AutoTrader.com plans to move its corporate headquarters to one of the towers at Perimeter Summit.

AutoTrader spokesman Mark Scott said Wednesday the company has signed a letter of intent to move into the 3003 Perimeter Summit building, about a half-mile from  its  current headquarters  in Dunwoody. He said some 1,200 to 1,400 employees will make the move.

"The idea is to consolidate all the employees into one building," said Scott, adding employees will move from a couple of places in Dunwoody, starting in the second half of 2010.

AutoTrader had been shopping for 250,000 square feet of space, according to commercial real estate services firm Jones Lang LaSalle. That would be one of the largest office leases in terms of square footage in metro Atlanta this year.

Scott said he could not confirm the amount of space the company will occupy at Perimeter Summit . The 3003 Perimeter Summit building is an 18-story, 390,000-square-foot Class A office tower, according to its Web site. Scott  declined to give the value or  length of  the lease.

AutoTrader is one of the nation's largest online classified marketplaces for automobiles. It  is owned by Atlanta-based Cox Enterprises.