Pridiyathorn, who is also finance minister, said the ambassadors had asked for details about the bidding for the new mass-transit routes.

He said the ambassadors from Britain and Germany had also enquired about details of the bidding, adding that the government's policy was to open the bidding to all interested parties.

"There will be no prefixing of construction specifications," he said.

Under the administration of ousted PM Thaksin Shinawatra, companies like Siemens and Alstom expressed interest in the mass-transit projects. The five routes are expected to cost a combined Bt165 billion.

The Thaksin government had promised that fares for the routes, once all five were completed, would be fixed at Bt15 a trip.

Pridiyathorn, however, said it would be difficult to keep all fares at that rate.

"The government does not wish to

 subsidise the [transit] fares for Bangkokians with tax money from provincial residents," he said. Current fares already range from up to Bt40, he said, adding that there would be further discussions on the fare structure.

Pridiyathorn said financing the Bt165-billion transit expansion would not be a problem, even though the Japan Bank for International Cooperation (JBIC) had signalled a reluctance to fund it.

He said the first three routes would be built in five years. This would give the government ample time to negotiate financing sources or tap its own investment funds.

The Finance Ministry last week said that it was negotiating with the Asian Development Bank for funding. Previously, it said the JBIC would be the only source of financing.

Pridiyathorn said the design-and-build model would be used for underground construction, while the detail-and-design model would be used for routes above ground. He said an independent adviser would design the projects and that the design would be the standard the government used when comparing bids.