Construction work is scheduled to start early next year on a £320m national stadium at Wembley.

Lottery-backed client English National Stadium Company this week struck a deal to purchase the existing stadium from leisure group Wembley plc. The company will pay for the stadium with £103m of a £120m Sports Council lottery grant earmarked for the project.

The client will formally appoint a Foster and Partners/HOK/Lobb team as architect of the 88 000-seat stadium next week.

A Mott MacDonald/Connell Wagner/Weidlinger Associates/Modus team will be structural engineer, with Mott MacDonald/ M-E/Connell Wagner as M&E engineer and Franklin & Andrews as QS.

Client chief executive Bob Stubbs said he hopes a design for the stadium will be submitted to Brent council for planning consent in July.

Stubbs said: "The team have already done some preliminary design work on the possible size, layout, configuration, and quality and cost of the stadium. We have developed a brief for them and they are now ready to start with the detailed design." Quizzed about the fate of Wembley Stadium's twin towers, Stubbs said: "We have a whole range of design options, one of which involves demolition of the twin towers, that we will be evaluating in discussion with Brent council and English Heritage." Stubbs estimated base construction costs at £160m-180m and said the trust would tender for a contractor "in the late third quarter or early fourth quarter of 1999".

He added: "In the best case scenario, we will have planning consent by January 2000 and we can start on site a couple of months after that." Stubbs said the project will be completed in the "early fourth quarter" of 2002.

Some £200m has also been raised from the City to fund construction of the new stadium. The redevelopment plan will see the 75-year-old stadium, often criticised for its shabby facilities and poor sightlines, transformed into a state-of-the-art arena.

It will form the centrepiece of England's 2006 World Cup bid, and could also be used in any future bid for the Olympic Games.

English National Stadium Company is a subsidiary of the Football Association, which will also pump money into the redevelopment project. It will also guarantee that the new stadium will be used for England matches and FA Cup finals.

Wembley plc will retain ownership of Wembley Arena, Wembley Conference and Wembley Exhibition Centre.