The Brisbane-based fund manager paid $22 million for two titles covering three distinct sites at 42-46 and 48-50 La Trobe Street in a deal that may prove controversial with heritage activists.

The two buildings on the site have been targeted by the Melbourne Heritage Action group in an attempt to protect the 1890s-built structures from demolition.

A heritage listing for the entire streetscape was rejected by Melbourne city councillors almost three years ago despite support from planning and heritage officers.

Fitzroys director Rob Harrington said the sale price for the 1103-square-metre holding reflected a land rate of almost $20,000 per square metre.

One portion of the site was separated from the others by the council-owned Bell Place laneway, he said.

The block between La Trobe, Exhibition, MacKenzie and Russell streets has become a development hotspot.

The 35-level Trillium Apartments is currently under construction on a neighbouring site where the historic Burton livery building was demolished. Nearby, Malaysian developer UEM Sunrise has proposed a 37-level residential tower at 9-23 MacKenzie Street.

The six-level office at 42-46 La Trobe Street has two duplex penthouse apartments at the top of the building. The older, two-level, historic building next door is used as an office.

Blue Sky has an active development pipeline in Brisbane where its real estate arm expects to launch at least five new projects in the city's south side this year and aims to build 1000 apartments within the next two years, according to reports.