The writ, anticipated since early this year, alleges that Mott MacDonald failed to prepare a steelwork design that could be produced within the cost plan.
The contractor, which has since been renamed as Brookfield, also alleges that Mott MacDonald made a series of design changes which were beyond the scope of normal design development.
Mott MacDonald has always denied any responsibility for problems on the ВЈ757m stadium, which was completed over a year late.
Multiplex is still locked in a battle with Darlington-based Cleveland Bridge, although it has now settled its dispute with PC Harrington.
ADVERTISEMENTIn a statement, Mott MacDonald said: "Mott MacDonald confirms that it has received a claim from Brookfield Construction (UK) Limited (formerly Multiplex Constructions (UK) Limited) against it as leader of the Mott Stadium Consortium (MSC), alleging breaches of contract in relation to structural engineering design work undertaken on Wembley Stadium by the consortium’s members.
"We would point out that Brookfield assumed responsibility for designing and building the stadium and MSC provided structural design consultancy services to Brookfield for the permanent structure.
"MSC was not responsible for project management or construction, which was the clear responsibility of Brookfield. We are in no doubt that MSC performed its obligations to Brookfield professionally and diligently.
"Mott MacDonald emphatically denies any liability for Brookfield’s loss and will vigorously defend the claim.
"We do not wish to comment in detail on any figures mentioned in the claim except to say they are not credible.
"We are confident that we will demonstrate that MSC fulfilled its obligations and has no liability for any loss Brookfield may have incurred."
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