The five rail routes are an extension of the Blue Line from Bang Sue to Hua Lamphong, the Purple Line from Bang Yai to Bang Sue, the Red Line from Rangsit to Bang Sue, the Green Line from Bangwa to Saphan Mai, and the Light Green Line from Prannok to Samut Prakan.

The 118-kilometre-long lines will need an investment of about Bt165.4 billion and bidding is expected to start next March, with the process completed before 2008.

Sombat Kitjalaksana, managing director of Bangkok Metro, which operates the subway, said the company and its partners were ready to bid for the operation of all five electric rail routes.  He added that parent Ch Karnchang was also ready to bid to construct the lines.

Italian-Thai Development is also ready to bid jointly for the project in an attempt to control at least 30 per cent of the Bt165.4-billion budget, the company's management said.

Chanachai Leenabanchong, managing director of Gold Plan Development construction company, said he was negotiating with partners from China and Japan to construct the lines.     "We are a smaller construction firm that cannot bid by ourselves, but with our partners we will make up the biggest group and we may be subcontracted to construct part of the project."

He said increased demand for cement and steel would inflate costs. All developers have to fix their construction costs, which is complicated by fluctuating raw-material prices, he added.

Ascon Construction also plans to acquire a construction company that has experience in state projects as a means to bid for infrastructure jobs in the next year, the company's CEO Pattanapong Tanumathaya said. The firm is negotiating with Chinese partners over a bid for construction projects in the next year.

Somluck Srimalee, The Nation