onstruction contracts for the 80,000-seat stadium for the 2012 Olympic in London and the 15,000-seat, $490 million Aquatics Centre have been signed with Team Stadium, led by Sir Robert McAlpine Ltd., Hemmel Hempstead and Balfour Beatty Construction Ltd., London, respectively. The stadium’s $990-million design-build contract is due to start next month after more than a year’s negotiations. The Olympic Development Authority plans to sign the 6,000-seat Velodrome contract within weeks with an undisclosed bidder.