MR EUGENE Larkin's Ardmore Building Company has paid in the region of £360,000 for a development site overlooking the Royal Canal at Castleknock, Dublin 15. The 2.3-acre site, which was owned by the British Margarine Company, was withdrawn at a Lisney auction in November and sold in subsequent negotiations. One acre is zoned for amenity use along the canal. The new owners are to seek permission for 40 two-bedroom apartments.