Local and international contractors are set to submit turnkey bids by 11 January 2003 for the US$2bn design and construction of two additional underground lines on the Tehran metro in Iran. Alstom of France, Siemens of Germany and Bombardier of Canada are believed to be among the interested firms. China International Trust and Investment Corporation (CITIC) is also expected to show strong interest in the scheme because it has already completed the first three sections of Line 1 and nearing completion on the fourth section. The latest project covers the design and construction of lines 3 and 4. About 24km of the 37km long Line 3 will be built underground, while some 19km of the 24km Line 4 will be tunnelled.