By Mark Court.A joint venture led by Sir Robert McAlpine has won the £90 million contract 110 on the £1,800 million extension to London Underground's Jubilee Line.London Underground has sent the joint ventures a provisional letter of intent which promises them the job as soon as the project gets government approval.German tunnellers Wayss and Freytag and French groundworks specialist Bachy are the joint venture partners for the job, which involves tunnelling from Canary Wharf to Canning Town and building Greenwich station.Bids from Birse/Bilfinger and Berger and Trafalgar House/Spie Batignolles/Cogefar also received close attention from London Underground, but the hopes of both groups seemed to have been dashed a few weeks ago. It is not known which of the two groups is being kept in reserve for the job.Sir Robert McAlpine now faces an anxious wait until November 12, when the Government should announce the fact of the Jubilee Line extension in its autumn statement.Contract 110 involves tunnelling in a mixture of strata from Canary Wharf to Canning Town. The section of the extension includes tunnelling beneath the Thames twice and constructing the tunnel portal.Construction of a station on a contaminated site in Greenwich is also included in the job. The station is planned to serve a huge mixed development British Gas wants to develop on a former gasworks site covering 120 ha.Greenwich Council has just agreed to give outline planning permission for the £1,000 million scheme, provided a number of conditions can be agreed.The outline plans include a so-called central business district of 1.5 ha focused on the Jubilee Line station. Up to 70,000 sq m of office space is proposed around the station along with high density residential accommodation. The remainder of the Greenwich peninsula site would be used for up to 5,400 residential units, offices, shops and parks.Work could start next year on decontamination of the peninsula.