One of Birmingham’s highest profile office schemes is beginning to silence its doubters after securing a third letting in as many months.

International architects Aedus have taken 5,000 sq ft on the ground floor of Colmore Plaza with a view to establishing its regional headquarters at the development.

Colmore Plaza, which was developed by Abstract Land on the site of the old Post and Mail tower before being acquired by global private equity group Carlyle Group, initially struggled to find occupiers as the market turned following its completion at the beginning of 2008.

The building’s first occupiers were Davis Langdon, the construction consultants on the project, which took a floor following the building’s completion.

However, after a quiet year where it is believed the scheme came close to securing some of the larger deals in the city such as Wragge and Co’s proposed move to Snowhill, Colmore Plaza has secured three new lettings since the summer.

The other successes include a deal with serviced office provider Orega, which took 20,000 sq ft, and engineering consultancy Amey which has taken 46,000 sq ft for its European design hub.

Relocating from its current office on Hagley Road in Birmingham, Aedas intends to establish its Midlands headquarters at Colmore Plaza, which will also act as a national meeting hub for the company’s international and regional offices.

The Aedas team at the building will include Marcus Wilkins, the newly appointed Division Director of Healthcare Architecture for the UK, as well as the team which originally worked on the design of Colmore Plaza in 2005. Fit out work is expected to begin in spring 2010.

Dan Beddow, Director at Aedas, said: “The space at Colmore Plaza provides us with a unique opportunity to create a design workspace and marketing hub that is imaginative and truly flexible.

“With both the building and the fit-out designed by our own team, we are in a perfect position to create a regional headquarters that works for the entire company’s needs.

“When designing Colmore Plaza, our objective was to deliver a building that embodied presence, flexibility and vitality articulated through refined and robust modern architecture.

“The result was a building with the highest specification of any office building outside London.

“Naturally, our decision to relocate into the space expresses our confidence in the building as a landmark premises for us as a global practice as well as being the perfect show case of what Aedas can achieve.”