The NATO headquarters project in Brussels has been thrown into further disarray after the Skidmore, Owings & Merrill architect in charge of the project quit the practice

Larry Oltmanns, a partner with 30 years of experience at SOM, left the firm after an executive board meeting last week.

This followed a round of redundancies three weeks ago in which the Nato bid’s senior designer, Michel Mossessian, lost his job.

This latest news has come as SOM met NATO chiefs to discuss the problems that have beset the project.

The scheme has suffered many delays, primarily because it has been managed by all 26 NATO states and the fact that the brief had to be referred back to six new members after they joined the organisation. Construction was due to begin in January and finish in 2008, but will now not be completed until 2011 at the earliest.

SOM architects stopped work this week until the management issues were sorted out, amid fears it could turn into another Scottish parliament.

Nato sources said that the organisation was happy with SOM’s concept design and was poised to appoint a project management team.

We have a lot of US schemes and have to get the right skills in the right place

Mark Regulinski, SOM partner

Meanwhile, following Oltmann’s departure, SOM has restructured its London office. Roger Kallman, who had been one of three partners at the London office, becomes consulting director. Mark Regulinski, the third partner, is to move to SOM’s New York office.

Regulinski said his move reflected an attempt by the firm to associate projects with its 31 partners instead of its main offices. It is understood that the volume of work in the USA, which includes partnering Daniel Libeskind on the Freedom Tower project at the World Trade Centre site in New York, is a more pressing priority than work in the UK and Europe.

Regulinski said: “We have to reconcile the partnership, where the directors are and the professional resources with what work is in the office. We are working on a lot of big mixed-use schemes in the USA and we have to get the right skills in the right place.”

Regulinski declined to comment on the reasons behind the departures of Oltmanns and Mossessian.