A pair of dated former Queensland Government buildings in Brisbane CBD will merge and be increased in height by six storeys as part of a new commercial development.

Ashe Morgan and DMANN Corporation submitted a development application to the Brisbane City Council in December 2017 proposing the re-purposing and redevelopment of the former Forestry and Health building at 163 Charlotte Street.

The Midtown Centre at 155 Charlotte Street and 150 Mary Street has been approved by the council.

The council gave the development the green light on Friday.

The development, called Midtown Centre, involves in-filling the two towers from level seven to 20 and incorporating an additional six storeys to create a single integrated tower.