Five companies submitted bids for the engineering and procurement (EP) contract in early 2001. They were France's Sofregaz, which was ranked second after the evaluation of proposals, Germany's Pipeline Engineering (PLE), South Korea's Daelim Engineering & Construction Company, Italy's Snamprogettiand OIEC. The local firm is understood to have bid to carry out the project without a foreign partner.

NIGC's tender had initially called for the installation of 12 compressor stations along the route of the line, but the scope was later reduced to six. The compressors will process gas to be pumped through the IGAT 3 trunkline from Bandar Assaluyeh, the onshore treatment centre for the South Pars offshore gas fields, to Saveh, southwest of Tehran. The line aims to boost gas flows to the north of the country.

NIGC is also pressing ahead with the fourth gas trunkline (IGAT 4). The company has invited bids by 12 February for the EP contract for eight compressor stations along the proposed route of the line.

It is understood that the 25-MW industrial turbines for the compressor units on both trunklines will be supplied by France's Alstom. The deal is part of a larger framework agreement signed in July between Alstom and NIGC for the French company to supply 50 25-MW turbines over a period of five years.

The tendering of the IGAT 4 compressor stations contract follows the completion of the first comprehensive study into the feasibility of the line by PLE in late 2001. According to PLE's study, IGAT 4 will have a length of about 700-800 kilometres and a 56-inch diameter. It will be designed to transport 110 million cubic metres a day of gas from South Pars and the onshore Tabnak field to the north.