The mega site on Athllon Drive was listed for sale on Friday and could house 100,000 square metres of office space, more than 1000 apartments or more than 120 townhouses thanks its flexible CZ2 zoning.

CBRE Canberra and Ray White Commercial are selling the block, opposite the Department of Human Services and the Department of Social Services, via expressions of interest.

The southern part of the site comes with a 4558-square-metre warehouse leased to the National Archives of Australia until March.

The block, which is ripe for a mixed-use precinct or public service hub, could be purchased in full or in two equal parts, subject to a subdivision.

CBRE Canberra associate director Mark Nicholls said he expected the site to attract a range of prospective buyers.

"Someone could do a mixed-used development and potentially divide half the site into office space and residential," he said.

"Somebody might buy that southern half where the warehouse is to utilise the warehouse."

CBRE managing director Andrew Stewart said the rare development opportunity could take advantage of existing public servants.

"Not too many opportunities of this size come onto the market," he said.

"Because of the size of the site, you can do townhouses, you can do apartments or you might wait and try and jagger a commonwealth department for an office space not too dissimilar to the Louisa Lawson Building.

"Given the Department of Social Services and the Department of Human Services are the largest occupants in the area, that's certainly an option."

Mr Stewart said he had also received interest from aged care operators.

Ray White Commercial Canberra director Andrew Smith said the block's requirements enabled a prospective buyer interested in a high-density, residential project to create a master plan and stage the development over time.

He expected a local developer who "understands the Tuggeranong precinct" to snap up the block.

Greenway is undergoing something of a revival with a swathe of new medium to high density projects planned or under construction on the edge of Lake Tuggeranong.

The latest site for sale at the opposite end of the town centre is located next to the proposed new suburb of Thompson as the ACT government looks to develop land west towards the Murrumbidgee River corridor.

Mr Smith said further development in the region would be a bonus for prospective buyers of the 26,000-square-metre block for sale.

"Any growth in the Tuggeranong Town Centre and population around the town centre would be beneficial to the owner of the site," he said.

"The site's westerly outlook towards the Brindabellas is something that will also be attractive to all occupants."

Mr Nicholls said any development of the block would also boost traffic through the town centre.

"The amount of dwellings you could potentially build on that site will certainly increase the population of the town centre and have a positive impact in more than one way."

Expressions of interest for the block at 76 Athllon Drive, Greenway close on December 1 at 4pm.