• Balfour Beatty win £154m contract to make venue multipurpose • Concerns grow over the role of West Ham in long-term plans The cost of the Olympic Stadium has risen to more than £580m, most of it met by taxpayers, with the news that Balfour Beatty has been awarded the £154m contract to transform the venue into one suitable for football and athletics. The appointment of a contractor to oversee the transformation of the temporary 80,000 seat structure into one with a cantilevered roof, permanent …