The move coincides with MDA's acquisition of Headlam's branding and design firm X-BBE Consulting.
MDA chairman Simon Metcalf said the acquisition would allow the firms to pool resources and services. He said: "By joining forces, we can offer a strategic consultancy across a wide range of sectors and beyond MDA's traditional markets."
Headlam, a former RICS director, formed X-BBE in 1996. The firm offers strategic business and branding advice to clients including the Millennium Commission, Woolwich and the Royal Institute of International Affairs.
The firm was appointed earlier this year by the Millennium Commission to investigate architects' commitment to sustainable design.
Other X-BBE clients include construction firms such as MDA rival Gardiner & Theobald and consultant Dearle & Henderson.
Headlam's appointment follows a troubled 18 months for the firm, which was hit by a £2.5m loss for the 15 months to 30 September 2000.
MDA, which has offices in the UK, Hong Kong and Germany, was hit by premature profit recognition, overvaluation of work in progress and poor credit control.
One source close to the firm said MDA's upcoming figures for the year to September 2001 would be crucial. The source said: "There must be proof that there are enough big future projects coming through."