Shui On, Gammon and China Civil Engineering are among the 12 top contractors included in six construction groups shortlisted by the Mass Transit Railway Corporation (MTRC) for its $4.9 billion Quarry Bay extension. Work on the route is expected to start in the summer and will be the first extension to the network since the Kwun Tong/Quarry Bay link was completed in 1989. It is also the first of four big capital projects, worth about $60 billion, the MTRC hopes to start in the next five years. The Quarry Bay extension will extend the Kwun Tong line through Mount Parker to North Point station where a cross-platform interchange will connect with the Island Line. About 3.5 kilometres of new track will be laid in twin tunnels. The chosen firms are: Shui On in a joint venture with mainland firm China Civil Engineering, Amec of Britain and Spie Batignolles of France; Gammon with associate companies Kvaerner Construction and Kvaerner Cementation; Britain's Balfour Beatty in a joint venture with Aoki of Japan; Dragages of France; Nishimatsu of Japan; and Japan's Kumagai Gumi Co which is bidding from Singapore. The project's aim is to reduce congestion, especially during rush hour when about 30,000 passengers pass through Quarry Bay station every hour. The station has a capacity of 36,000 people an hour. Cash for the project will come from borrowings the MTRC plans to arrange towards the end of the year. The Corporation needs more than $55 billion for its new projects. These include the Quarry Bay scheme, the $24-billion Tseung Kwan O extension, the East Kowloon and North Island lines together worth about $30 billion, and an $8 billion system-wide station improvement programme.