Canadian-based developer Daon Corp. has bought up about three-quarters of the 1300 block of New York Avenue NW and plans to put up what Daon believes will be the single largest commercial and retail building in the District.

The 12-story building will contain 1.2-million square feet of gross space, including parking and core areas, and will have about 730,000 square feet of rentable office space, a spokesman for Daon said.

Prudential Insurance Co., owner of a new office building at 15th and L streets NW and 37 acres under development in Prince George's County, will finance the $160 million construction project and will retain an equity interest in it, the spokesman said.

Daon set a record last April when it paid $615 a square foot, a total of $40 million, for one of the parcels on the block. That piece was acquired from a partnership headed by developer Dominic F. Antonelli Jr. The parcel was once the site of the huge Capital Garage, which was torn down a few years ago.

Now Daon, based in Vancouver, has bought three other pieces in the same block that are also needed for the building, at a total of $9.7 million, and the firm is to go to settlement on one last parcel, to be bought at an undisclosed sum, on Jan. 6.

The three recently purchased pieces were 1332 New York Ave., bought from GFM Inc. for $2.4 million; an adjacent property from H. Abramson and others for $3 million; and 1328-1330 New York Ave. from 1328 New York Avenue Associates for $4.3 million.